BookPDF Available

The conservation status of marine biodiversity of the western Indian Ocean

Authors:

Abstract and Figures

The Western Indian Ocean (WIO) is comprised of productive and highly diverse marine ecosystems that are rich sources of food security, livelihoods, and natural wonder. The ecological services that species provide are vital to the productivity of these ecosystems and healthy biodiversity is essential for the continued support of economies and local users. The stability of these valuable resources, however, is being eroded by growing threats to marine life from overexploitation, habitat degradation and climate change, all of which are causing serious reductions in marine ecosystem services and the ability of these ecosystems to support human communities. Quantifying the impacts of these threats and understanding the conservation status of the region's marine biodiversity is a critical step in applying informed management and conservation measures to mitigate loss and retain the ecological value of these systems. The International Union for Conservation of Nature (IUCN) Red List Categories and Criteria are the most widely used and objective system of quantifying the conservation status of species. For this report, Red List assessments for marine fish species were produced and compiled with existing assessments for other marine species groups to generate a comprehensive assessment of the conservation status of the marine biodiversity of the WIO. The species assessed for this report were done so through clade-based and regionally focused Red List assessment workshops involving hundreds of taxonomic experts from around the world. To supplement assessments for marine fishes of the region, three workshops were held in Tanzania, Oman and South Africa over the course of three years from 2017 to 2019. Thirty-one marine fish experts from 14 countries participated in the three workshops. Among the more than 4,000 species assessments compiled for this report, 473 species were identified as threatened or Near Threatened with extinction at the global level, according to the IUCN Red List Categories and Criteria. Incorporating uncertainty in the true status of Data Deficient species, between 7-24% of all species were estimated as being currently at risk of extinction, with a best estimate of 8% of all assessed species being threatened. Spatial analyses of species richness across the region identified hotspots of threatened species including the southern Red Sea and the southern coast of India. Major threats were analysed amongst threatened and Near Threatened species, of which more than 90% were found to be impacted by biological resource use, largely in the form of targeted fisheries and bycatch as well as illegal, unreported and unregulated fishing activities. Overexploitation was flagged as a driver of population decline for all threatened and NearThreatened cartilaginous fishes, mammals and sea turtles. The 237 threatened and Near Threatened reef-building corals are impacted by the same suite of fishing threats, including fisheries-related habitat degradation. In general, habitat degradation and destruction through pollution, coastal development and other habitat modifications emerged as a major threat across assessed species groups. From these analyses, this report highlights trends in research needs for species in the region, including priorities for fundamental biological and ecological research and quantifying trends in the populations of species. Overall, with a best estimate of 8% threatened species, the conservation status of the Western Indian Ocean region is moderately high, relative to the status of the same taxonomic suite of species assessed in other regions. This comparatively high level of threatened biodiversity highlights the importance of timely and targeted conservation actions for the biodiversity of the region moving forward. The region has the highest levels of uncertainty in species status with 16.9% of the WIO species listed as Data Deficient, as compared to 11.0-15.8% in other tropical regions. The analyses presented here also highlight particularly threatened and susceptible taxonomic groups, geographical hotpots of conservation priority as well as trends in major anthropogenic threats. The assessments and analyses submitted in this report should inform conservation decision-making processes and will be valuable to policymakers, natural resource managers, environmental planners and NGOs.
Content may be subject to copyright.
THE CONSERVATION STATUS OF MARINE
BIODIVERSITY OF THE WESTERN INDIAN
OCEAN
The IUCN Red List of Threatened SpeciesTM - Regional Assessment
R. Bullock, G. Ralph, E. Stump, F. Al Abdali, J. Al Asfoor, B. Al Buwaiqi, A. Al Kindi, A. Ambuali,
T. Birge, P. Borsa, F. Di Dario, B. Everett, S. Fennessy, C. Fonseca, C. Gorman, A. Govender,
H. Ho, W. Holleman, N. Jiddawi, M. Khan, H. Larson, C. Linardich, P. Matiku, K. Matsuura,
C. Maunde, H. Motomura, T. Munroe, R. Nair, C. Obota, B. Polidoro, B. Russell, S. Shaheen,
Y. Sithole, W. Smith-Vaniz, F. Uiblein, S. Weerts, A. Williams, S. Yahya, K. Carpenter
INDIAN OCEAN
WESTERN
About IUCN
IUCN is a membership Union uniquely composed of both government and civil society organisations. It
provides public, private and non-governmental organisations with the knowledge and tools that enable human
progress, economic development and nature conservation to take place together. Created in 1948, IUCN
is now the world’s largest and most diverse environmental network, harnessing the knowledge, resources
and reach of 1,400 Member organisations and some 15,000 experts. It is a leading provider of conservation

repository of best practices, tools and international standards. IUCN provides a neutral space in which diverse
stakeholders including governments, NGOs, scientists, businesses, local communities, indigenous peoples’
organisations and others can work together to forge and implement solutions to environmental challenges and
achieve sustainable development.
Working with many partners and supporters, IUCN implements a large and diverse portfolio of conservation
projects worldwide. Combining the latest science with the traditional knowledge of local communities, these
projects work to reverse habitat loss, restore ecosystems and improve people’s well-being.
www.iucn.org
https://twitter.com/IUCN/
IUCN – The Species Survival Commission
With over 8,000 members, the Species Survival Commission (SSC) is the largest of the six expert commissions

knowledge on the status and threats to species, providing advice, developing policies and guidelines,
facilitating conservation planning, and catalysing conservation action.
Members of SSC belong to one or more of the 140 Specialist Groups, Red List Authorities, Task Forces and
Conservation Committees, each focusing on a taxonomic group (plants, fungi, mammals, birds, reptiles,

reintroduction of species, wildlife health, climate change and conservation planning.
www.iucn.org/theme/species/about/species-survival-commission
twitter.com/iucnssc
IUCN – Global Species Programme
The IUCN Global Species Programme supports the activities of the IUCN Species Survival Commission and
individual Specialist Groups, as well as implementing global species conservation initiatives. It is an integral
part of the IUCN Secretariat and is managed from IUCN’s international headquarters in Gland, Switzerland.
The Species Programme includes a number of technical units covering Species Trade and Use, the IUCN Red
List Unit, the Freshwater Biodiversity Unit (all located in Cambridge, UK), the Global Biodiversity Assessment
Initiative (located in Washington, DC, USA) and the Marine Biodiversity Unit (located in Norfolk, Virginia, USA).
www.iucn.org/species
THE IUCN RED LIST OF THREATENED SPECIES™ – REGIONAL ASSESSMENT
THE CONSERVATION STATUS OF MARINE
BIODIVERSITY OF THE WESTERN INDIAN
OCEAN
R. Bullock, G. Ralph, E. Stump, F. Al Abdali, J. Al Asfoor, B. Al Buwaiqi, A. Al Kindi, A. Ambuali,
T. Birge, P. Borsa, F. Di Dario, B. Everett, S. Fennessy, C. Fonseca, C. Gorman, A. Govender,
H. Ho, W. Holleman, N. Jiddawi, M. Khan, H. Larson, C. Linardich, P. Matiku, K. Matsuura,
C. Maunde, H. Motomura, T. Munroe, R. Nair, C. Obota, B. Polidoro, B. Russell, S. Shaheen,
Y. Sithole, W. Smith-Vaniz, F. Uiblein, S. Weerts, A. Williams, S. Yahya, K. Carpenter
The designation of geographical entities in this book, and the presentation of the material, do not imply the
expression of any opinion whatsoever on the part of IUCN or other participating organisations concerning the
legal status of any country, territory or area, or of its authorities, or concerning the delimination of its frontiers or
boundaries.

organisiations.
IUCN is pleased to acknowledge the support of its Framework Partners who provide core funding: Ministry
󰀨󰀨



Published by: IUCN, Gland, Switzerland
Copyright: © 2021 IUCN, International Union for Conservation of Nature and Natural Resources
Reproduction of this publication for educational or other non-commerical purposes is
authorised without prior written permission from the copyright holder provided the source is
fully acknowledged.
Reproduction of this publication for resale or other commercial purposes is prohibited
without prior written permission from the copyright holder.
 


Linardich, C., Matiku, P., Matsuura, K., Maunde, C., Motomura, H., Munroe, T., Nair, R.,
Obota, C., Polidoro, B., Russell, B., Shaheen, S., Sithole, Y., Smith-Vaniz, W., Uiblein, F.,
Weerts, S., Williams, A., Yahya, S., Carpenter, K. (2021). The conservation status of marine
biodiversity of the Western Indian Ocean. Gland, Switzerland: IUCN. vii + 32 pp.
ISBN: 978-2-8317-2098-2 (PDF)
Cover photos: Front - Coral Reef, Zanzibar © F. Di Dario.
Chaetodon melapterus by D.P.
Wilson and licensed under CC BY 2.0
Photographs used in this publication remain the property of the original copyright holder and are licensed as either
standard copyright (©) or Creative Commons Attribution 2.0 Generic (CC BY 2.0). See individual captions for
details. Photographs under standard copyright should not be reproduced or used in other contexts without written
permission from the copyright holder (see individual caption for photographer). Photos licensed under Creative
Commons Attribution 2.0 are the work of D.P. Wilson and should not be reproduced without proper attribution. Note

 
Available from: IUCN, International Union for Conservation of Nature
Rue Mauverney 28
1196 Gland, Switzerland
Tel +41 22 999 0000
Fax +41 22 999 0002
www.iucn.org/resources/publications
More information on the IUCN Red List is available on www.iucnredlist.org.
Table of Contents
Acknowledgements ............................................................................................................................................iv
Executive summary .............................................................................................................................................v
Commonly used acronyms...............................................................................................................................vii
1. Background
1.1 The Western Indian Ocean region ................................................................................................. 1
1.2 Biodiversity and endemism ............................................................................................................2
1.3 Threats to marine biodiversity ....................................................................................................... 3
1.4 Assessment of extinction risk: IUCN Red List of Threatened SpeciesTM ....................................... 3
1.5 Project objectives ..........................................................................................................................4
2. Methods
2.1 Geographic scope .........................................................................................................................6
2.2 Taxonomic scope ........................................................................................................................... 6
2.3 Preliminary assessments and pre-workshop data collection ......................................................... 7
2.4 Red List assessment workshops ................................................................................................... 7
2.5 Post-workshop review ...................................................................................................................7
2.6 Methodology for spatial analyses .................................................................................................. 8
3. Results and discussion
3.1 Conservation status of marine biodiversity .................................................................................... 9
3.2 Trends by taxonomic group ......................................................................................................... 10
3.3 Spatial distribution of species ...................................................................................................... 12
3.4 Threats ........................................................................................................................................ 15
3.5 Research needs ..........................................................................................................................17
  .......................................................................................................... 18
3.7 Species conservation successes .................................................................................................19
4. Conclusions
4.1 Overview ..................................................................................................................................... .20
4.2 Application of project results ........................................................................................................21
4.3 General conservation strategies and tools .................................................................................. 22
4.4 Next steps ....................................................................................................................................23
References ........................................................................................................................................................ 25
Appendix: Expert participants ........................................................................................................................ 31
iii
Acknowledgements
This project represents a major expansion of the
IUCN Red List process in the Western Indian
Ocean and could not have been completed
without numerous donors and hundreds of
experts. The most recent assessments were
completed with the generous support of the
Total Foundation and Toyota Motor Corporation.
We thank The Deep and Oceanario de Lisboa
for their support of marine IUCN Red Listing
partnerships, which have contributed greatly to
the assessments in this report.
IUCN’s Red Listing process relies on the
willingness of scientists to contribute and
pool their collective knowledge on species, in
order to make the most reliable and up-to-date
assessments. Without such commitment, this kind
of regional overview would not be possible. We
would therefore like to acknowledge and thank all
of the people who gave their time and valuable
expertise during the assessments. Thanks to

their guidance and support of the Global Marine
Species Assessment initiative of IUCN’s Global
Species Programme Marine Biodiversity Unit
since its inception.
We extend our gratitude to the Oceanographic
Research Institute of the South African
Association for Marine Biological Research,
especially Dr. Larry Oellermann and Ramini
Naidoo, for hosting the third Red List workshop
and providing logistical assistance. We also thank
󰀨
hospitality during the second Red List workshop.
󰀨


peer-reviewers for their helpful comments that
improved this report.
iv
Spotted Sharpnose (Canthigaster solandri
CC BY 2.0
Executive summary
The Western Indian Ocean (WIO) is comprised of
productive and highly diverse marine ecosystems
that are rich sources of food security, livelihoods,
and natural wonder. The ecological services
that species provide are vital to the productivity
of these ecosystems and healthy biodiversity is
essential for the continued support of economies
and local users. The stability of these valuable
resources, however, is being eroded by growing
threats to marine life from overexploitation,
habitat degradation and climate change, all of
which are causing serious reductions in marine
ecosystem services and the ability of these
ecosystems to support human communities.

understanding the conservation status of the
region’s marine biodiversity is a critical step in
applying informed management and conservation
measures to mitigate loss and retain the
ecological value of these systems.
The International Union for Conservation of
Nature (IUCN) Red List Categories and Criteria
are the most widely used and objective system
of quantifying the conservation status of species.
For this report, Red List assessments for marine

with existing assessments for other marine
species groups to generate a comprehensive
assessment of the conservation status of the
marine biodiversity of the WIO. The species
assessed for this report were done so through
clade-based and regionally focused Red List
assessment workshops involving hundreds of
taxonomic experts from around the world. To

region, three workshops were held in Tanzania,
Oman and South Africa over the course of three

experts from 14 countries participated in the three
workshops.
Among the more than 4,000 species
assessments compiled for this report, 473

Threatened with extinction at the global level,
according to the IUCN Red List Categories and
Criteria. Incorporating uncertainty in the true

of all species were estimated as being currently

all assessed species being threatened. Spatial
analyses of species richness across the region

the southern Red Sea and the southern coast
of India. Major threats were analysed amongst
threatened and Near Threatened species, of

by biological resource use, largely in the form of



population decline for all threatened and Near

and sea turtles. The 237 threatened and Near
Threatened reef-building corals are impacted


habitat degradation and destruction through
pollution, coastal development and other habitat

assessed species groups. From these analyses,
this report highlights trends in research needs
for species in the region, including priorities for
fundamental biological and ecological research
and quantifying trends in the populations of
species.
v

species, the conservation status of the Western
Indian Ocean region is moderately high, relative
to the status of the same taxonomic suite
of species assessed in other regions. This
comparatively high level of threatened biodiversity
highlights the importance of timely and targeted
conservation actions for the biodiversity of
the region moving forward. The region has
the highest levels of uncertainty in species


other tropical regions. The analyses presented
here also highlight particularly threatened and
susceptible taxonomic groups, geographical
hotpots of conservation priority as well as trends
in major anthropogenic threats. The assessments
and analyses submitted in this report should
inform conservation decision-making processes
and will be valuable to policymakers, natural
resource managers, environmental planners and
NGOs.
vi
Starry Moray (Gymnothorax nudivomer
BY 2.0
Commonly used acronyms
Red List Categories
 
 
 
 
VU Vulnerable
NT Near Threatened
LC Least Concern
 
 
International Organizations
IUCN International Union for
Conservation of Nature
SSC Species Survival Commission
SSG Species Specialist Group
RLA Red List Authority
MBU Marine Biodiversity Unit
FAO Food and Agriculture Organization
of the United Nations
Country Codes
BHR Bahrain
IOT British Indian Ocean Territory
(Chagos Archipelago)
COM Comoro Islands
 
 
 
ATF French Southern and Antarctic
Lands (Bassas da India, Glorioso


IND India
IRN Iran
 
ISR Israel
 
 
KWT Kuwait
MDG Madagascar
MDV Maldives
MUS Mauritius
MYT Mayotte
MOZ Mozambique
OMN Oman
PAK Pakistan
 
 
SAU Saudi Arabia
SYC Seychelles
SOM Somalia
ZAF South Africa
LKA Sri Lanka
SDN Sudan
TZA Tanzania
 
 
vii
1.1 The Western Indian Ocean region

diverse marine ecological system on the planet.
On its western periphery, covering approximately
30 million km² and spanning the waters of
32 countries and territories, lies the Western


northeastern range experiences heavy monsoon
rains while the northwestern range is bordered
by arid land and is characterized by large semi-
enclosed bodies of water such as the Red Sea.
Shallow coral reef, estuaries, seagrass and
mangrove systems are all found in coastal areas.
The contrasting habitats within the region may
󰀨
is likely to be higher where unique habitats occur
(Kier et al., 2009). Unfortunately, due to multiple
factors, this region is understudied and has much
to be discovered (Wafar et al., 2011).
The highly diverse marine biodiversity of the
WIO has been a rich source of food security,
livelihoods and natural wonder for the peoples

WIOMSA, 2015). The ecological services that
species provide are vital to the existence of these
marine ecosystems (Palumbi et al., 2009) and a
healthy biodiversity is essential for maintaining
a safe operating space for humanity (Rockstrom
et al., 2009). Unfortunately, growing threats
to marine life from overexploitation, habitat
degradation and climate change are seriously
impacting marine ecosystems globally (Halpern

reductions in marine ecosystem services and
the ability of the ecosystem to support human
communities (Worm et al., 2006).
Some of the most heavily impacted marine biotas
in the world are in the Western Indian Ocean
where drastic reductions in coral cover occurred
because of sustained heightened sea surface
temperatures and subsequent widespread
bleaching events in the late 1990s (Wilkinson et
al., 1999). Human population growth in the region
also poses substantial threats to the sustainability
of coastal biota: many of the countries in the
Western Indian Ocean are characterized by high
population growth rates, high population density,


1
1. Background
Figure 1: The boundaries of the Western Indian

and Bianchi (1984).
1.2 Biodiversity and endemism
The WIO is associated with areas of high species
richness and high endemism. It is ranked as one
of the world’s richest oceanic regions (Keesing


species known from the Western Indian Ocean

Across taxa, high levels of endemism have been
recorded in in the territorial waters of South
Africa, the Red Sea, India, Mauritius, La Reunion,
the Seychelles, India and the Maldives (Van der


DiBattista et al., 2016).
The productivity of the rich ecosystems of the
WIO has so far supported economies and
livelihoods in the region (Samoilys et al., 2015).
Fisheries form a large economic sector in most
nations, providing food security and employment
in coastal communities, and contributing to
national economies and GDPs (Carpenter et


WIOMSA, 2015). Fisheries in the Western Indian
Ocean region range from dynamic artisanal


of gears used in near-shore environments, to



pelagic long-lining and purse-seining (Cochrane



WIOMSA ,2015).
The biodiversity of the region supports a growing

has grown rapidly in recent years, and in some


Gossling, 2006). Tourists are drawn to the
region’s beaches, lagoons, coral reefs, wildlife,
and coastal cultural sites (Gossling, 2006).
Biodiversity also provides important aesthetic,
cultural and spiritual services to coastal
communities.
Knowledge of marine biodiversity in the

greatly from both internationally and locally
󰀨

(1959 to 1965) that supported participants from
20 countries, considerably enhanced knowledge
of marine biodiversity beyond shallow and easily
accessible waters. However, current marine
󰀨
across the region, varying according to the
󰀨
󰀨
the marine realm of the WIO remain (Wafar et al.,

2
Outside Malindi Fish Market, Zanzibar © G.
Saluta.
1.3 Threats to marine biodiversity
Historically low levels of economic development
in parts of the WIO have meant that, in some
areas, the marine ecosystem may have been less
impacted by coastal human activity. For example,
arid nations such as Somalia and Sudan have
low coastal populations densities due to lack of
freshwater and high temperatures, thus limiting
development and exploitation in the coastal

However, contemporary increases in growth
and development across the region are likely to
increasingly impact marine biodiversity. Previous
regional-scale work has highlighted “hotspots”

areas where high endemism combines with
multiple threats including coastal and industrial
development, global warming, pollution, and



portions of their mangrove shoreline, coral reefs
have declined due to major bleaching events
and overexploitation of pelagic and demersal


reported across vast areas of the WIO including
but not limited to the Arabian Gulf, Sri Lanka



to a loss of ecosystem services from reefs,
mangroves and seagrass beds as well as loss
of livelihoods, food security and tourism value
(Obura et al., 2017).
1.4 Assessment of extinction risk: IUCN Red
List of Threatened SpeciesTM

the principles of extinction risk theory (Mace
et al., 2008) and are the most widely used and
objective system of quantifying extinction risk
across all taxa except microbiota (e.g., Butchart

󰀨
There are nine Red List categories for global



Threatened (NT), Least Concern (LC), Data

2012).
Species that meet the quantitative thresholds

are assigned to one of the three threatened

come very close to, but do not fully meet the
thresholds for a threatened category, the Near
Threatened category is applied. When there
are no known major global-level threats, or
the known threats to a species do not reach
quantitative thresholds, a species is assessed as
Least Concern. When assessment data indicate


poorly understood due to taxonomic uncertainty
󰀨
Criteria cannot be applied until further research
is conducted, and the species is assigned to

category is used to indicate a species that is
recognized as valid, but that has not yet been
assessed against the Red List Criteria (IUCN,

List.
3
Figure 2: The IUCN Red List Categories.

or both of the two premises of extinction risk
theory: elevated risk of extinction occurs when (1)
species’ populations are small and/or (2) species
have experienced, are experiencing or are likely
to experience population declines at rates that
are biologically infeasible for the population to

https://www.iucnredlist.org/resources/categories-
and-criteria for more information on Red List
Categories and Criteria). Criterion A is commonly

threat(s) that cause a population reduction
beyond a species’ ability to naturally sustain itself.
The decline is scaled to the life history of the

as the average age of the parents of a cohort.
Criterion B addresses species with restricted
geographic range that are also characterized by

habitat or individuals. Two metrics are used to
describe the spatial distribution of extinction risk.

area of a minimum convex polygon that contains
all known or inferred occurrences, and Area of

is inhabited by the species. Criterion C is applied
to species with a naturally small population size
and an observed, inferred or estimated continued
decline of the number of mature individuals in a
population. Criterion D addresses species with
extremely small and/or restricted populations, and

risk probabilities to estimate extinction risk.
1.5 Project objectives
The conservation status of several important
species that constitute the rich marine
biodiversity of the Western Indian Ocean is
󰀨
󰀨
overcome this scenario, the IUCN Red List has
formed the basis for many regional conservation
planning initiatives. Additionally, IUCN Red List
assessments are essential to Key Biodiversity
Area (KBA) analyses. KBAs can be designated
as targets needing conservation action to protect
biodiversity with a larger taxonomic scope.
Findings from this project could provide a unique

KBAs with broad taxonomic coverage.
IUCN Red List assessments are a key tool used
in local, national, regional, and global biodiversity
conservation. Regional or national Red Lists
often form the basis of national listings for
species-at-risk around the world. For example,
in the USA, global Red List assessments for
reef-building corals were used as the basis for
a successful petition to list 88 species of corals

Act. Some mega biodiverse countries, such as
Brazil, also rely on IUCN Categories and Red
List assessments in order to build their national
conservation strategies and environment action
plans (ICMBio/MMA, 2018). In the WIO region,
re-assessments of the Red List status of reef-
building corals are in development, which will
track progress towards the Aichi Biodiversity
Targets and post-2020 biodiversity goals. South
Africa has included Red List status of marine
species in support of its National Biodiversity
Assessment (Van der Bank et al., 2019), as
well as in supporting rationale for its recently-
expanded MPA network (Skowno et al., 2019).
4
Diodon hystrix

licensed under CC BY 2.0.
There is a distinct need for critical information
to help progress towards international targets
for biodiversity conservation, such as the United
Nations Sustainable Development Goals (SDGs)
and the Strategic Plan for the Convention on
Biological Diversity (CBD). The aim of this project
was therefore to assess the conservation status
of WIO marine species and, alongside existing
assessments for other key species groups,
present these data as the foundation for strategic
conservation in the Western Indian Ocean region.



analyze trends in the conservation status
of all assessed marine biodiversity in the

analyze trends in major threats and
conservation needs across species to
inform a state-of-knowledge report that can
support regional marine and coastal planning

build an inter-disciplinary, inter-organizational
network of experts to champion the project

sustainably (e.g. mapping information).
5
Celebes Flathead (Thysanophyrs celebica
CC BY 2.0
2. Methods
2.1 Geographic scope

following Fischer and Bianchi (1984),
encompasses the United Nations Food and

51 as well as the entirety of Sri Lanka (Figure



includes 32 countries and territories, the majority
of which are considered developing economies
(UN, 2019). Major currents, including the Agulhas
Current, the Somali Coastal Current, the South

Current, impact the distribution and productivity of
biodiversity in the WIO.
2.2 Taxonomic scope

4,000 valid marine species in 10 taxonomic
and functional groups (Table 1). Within these
taxonomic groups, only valid species that are
primarily marine, native and present in the

published on the IUCN Red List are included.
Taxa below species level (i.e., subspecies) were
not assessed.
Taxonomy follows the standards adopted by
the IUCN Species Survival Commission (SSC)
Species Specialist Groups (SSGs) and Red List

taxonomic group. Higher taxonomic levels for

by Nelson (2006), and species-level taxonomy
follows that of the California Academy of

of Fishes (Fricke et al., 2020). It is expected that
the majority of Western Indian Ocean species
in these taxonomic and functional groups have

recently described or reported from the Western
Indian Ocean may have been omitted. As

the available assessments were supplemented
by three Red List assessment workshops focused
on species of the Western Indian Ocean.
6
Table 1: Number of Western Indian Ocean
species assessed in each of the 10 functional
groups included in this analysis.
Acanthurus sohal

under CC BY 2.0.
Functional Group Species
Mammals 46
Sea snakes 19
Sea turtles 5
 2990
Sharks and rays 264
Cone snails 183
Sea cucumbers 125
Reef-building corals 492
Mangroves 26
Seagrasses 17
2.3 Preliminary assessments and
pre-workshop data collection
The IUCN Red List methodology is an objective,
data-driven process based on extinction risk
theory. For each species, the respective IUCN
species authority (e.g., Species Specialist Group
and/or Red List Authority) led the assessment

compiled into IUCN’s Species Information Service
(SIS) database, including data on the taxonomic

status and trends, habitats and ecology, threats
and conservation measures.
2.4 Red List assessment workshops
The species included in this analysis were
assessed during global, clade-based Red List
assessment workshops involving hundreds of
taxonomic experts from around the world. Three

Western Indian Ocean were held in Zanzibar,



participated in the three workshops (see
Appendix for participant lists for each workshop).

overview of the project’s aim and scope, as well
as a short training in the use and application
of IUCN Red List methodology. During the
remainder of the workshops, experts were
separated into groups based on their taxonomic
expertise. Guided by one of the facilitators, the
experts reviewed the preliminary assessments
generated during pre-workshop data collection
󰀨
information as available. These data were then
used to determine if the thresholds and sub-
criteria were met for a threatened listing under at
least one Red List criterion for each species.
2.5 Post-workshop review
Following the workshops, each species’
assessment was edited, and outstanding
questions resolved through further consultations
with workshop participants, as well as with
members of the relevant Species Specialist
Groups and other experts who did not attend
the workshops. When necessary, distribution


review and consistency check completed by the
IUCN Red List Unit.
Three estimates for the proportion of threatened
species are used to account for the uncertainty
around the true extinction risk faced by Data

uses a midpoint and assumes the same
proportion of threatened species within the

categories. However, as the true status of Data

bound bracket of proportion threatened is also
calculated. The lower bound assumes that none

while the upper bound assumes that all Data

Table 2: The equations for the three estimates
of the proportion of threatened species based
on the IUCN Red List (IUCN, 2016). The
IUCN Red List categories include the three




Estimate Equation
Lower bound 
Mid-point 
Upper bound 
7
2.6 Methodology for spatial analyses


and habitat preferences, were used to generate
distribution maps in ArcGIS 10.5 (software

assessments, coastal species are understood
as species residing relatively near the shore
in depths shallower than 200 m. Maps for
󰀨
bathymetric layer, based on two-minute spatial
bathymetry data made available by the National
Marine Fisheries Service of the U.S. National
Oceanographic and Atmospheric Administration
󰀨
either 100 km from the coast or the 200 m
depth contour, whichever was further from the
coastline. This approach standardizes the way
coastal species are mapped and produces
uniform and comparable distribution maps. For
pelagic and deep-sea species, distribution maps
were digitized by hand relative to known depth
preferences and habitat requirements.
Species richness analyses were conducted
toevaluate biodiversity patterns in the Western
Indian Ocean region for: 1) assessed marine

the three threatened categories (Critically


all richness analyses, each species’ distribution
map was transformed into the World Cylindrical

into a square grid raster of 10 x 10 km cell size.

was assigned a value of “1”. For each richness
analysis, the selected rasters were added

represented the number of species that occupy
each grid cell within the region.
8
Synodus variegatus
CC BY 2.0
3.1 Conservation status of marine biodiversity
Across the more than 4,000 assessed marine
species of the Western Indian Ocean included

Concern (LC). These are primarily widely
distributed and abundant species, or those with
no known major threats. The three threatened
categories account for a relatively small number
of species, with 25 assessed as Critically

195 as Vulnerable (VU). Another 197 species
nearly met the thresholds and conditions for a
threatened listing and were assessed as Near
Threatened (NT). The remaining species were


Based on these species, the best estimate for

for the uncertainty surrounding the true status
of the species listed as DD, the percentage of


the DD species are threatened.

listed under criterion A, indicating a past, present
or future projected population decline. The
remaining species were listed under criterion B

species were listed under multiple criteria.
3. Results and discussion
9


3.2 Trends by taxonomic group
The number of assessed species and estimates
of percentage threatened varied widely by
taxonomic group (Figure 4, Table 3). Across
the taxa included here, the highest and lowest
percentage of threatened species occurred in the

occur within the WIO were considered
threatened, while none of the 19 species of sea
snakes were considered threatened. Seven of
the 46 marine mammals, including cetaceans,
pinnipeds and sirenians, were listed as


10
Figure 4: Percentage of species listed in each of the IUCN Red List categories by taxonomic group. CR –


Table 3: Number of species and estimates of the percentage of threatened species for each taxonomic group
included here. The percentage of threatened species estimates follow the recommendations in IUCN (2016).


are threatened, respectively.
Taxon Species Lower Midpoint Upper
Mammals 46   
Sea snakes 19   
Sea turtles 5   
 2990   
Sharks and rays 264   
Cone snails 183   
Sea cucumbers 125   
Reef-building corals 492   
Mangroves 26   
Seagrasses 17   
11

with over 17,000 valid species (Fricke et al.,


on about 2,200 species from southern Africa
(Namibia to Mozambique), Heemstra et al. (in
press) include well over 3,600 species of coastal


Heemstra, 1986), there are several pockets of





be described throughout the WIO, for example


Voronina, 2019) and Zanzibar, Tanzania (Tea et
al., 2019), indicating that our understanding of


from this region in the last decade. Among the

skates and chimaeras, the best estimate for the

Arabian Sea has one of the highest proportions of

et al., 2018). A relatively low proportion of bony

the nearly 3,000 species listed in a threatened
category.
Comprehensive conservation assessments
of invertebrates are limited in the WIO, with
assessments completed only for the cone
snails (Gastropoda: Conidae), sea cucumbers
(Holothuroidea), and reef-building corals
(Anthozoa: Scleractinia). In general, few cone


threatened.
The marine plants, mangroves and seagrasses,
are widely distributed in coastal regions. About

in the WIO region. These species provide
fundamental ecosystem services, including

processing, and sediment control, and support

around the globe (Costanza et al., 1997). Overall,
the risk of global extinction to these marine plants
remains low in the WIO, with only two species of
seagrasses listed as VU and one as DD.
Townsend’s Anthias (Pseudanthias townsendi
under CC BY 2.0
3.3 Spatial distribution of species
The highest richness of all assessed marine
species, with upwards of 1,300 species per 100
m², occurred in the tropics along the coast of

Lanka (Figure 5). Generally, richness was higher
󰀨
The shallow, semi-enclosed Persian/Arabian Gulf
was an exception, with lower overall richness

its relatively young geological age and harsh
environmental conditions (e.g., Sheppard et al.,
2010).
12
Figure 5: Distribution of the marine species of the Western Indian Ocean that have been assessed against the
IUCN Red List Categories and Criteria.
Figure 6: Distribution of the threatened marine species of the Western Indian Ocean that have been assessed
against the IUCN Red List Categories and Criteria.
The east coast of Africa (Kenya, Tanzania and
Mozambique), the Western Indian Ocean Islands,
the Red Sea, the southern coasts of India and
the coastal regions of Sri Lanka were areas with
highest numbers of threatened species, with
higher richness of threatened species in coastal
󰀨
the southern Red Sea and along the southern
coast of India, however, the number of threatened
species was higher than would be expected
based on the overall number of species alone.
13

assessed against the IUCN Red List Categories and Criteria.

distributed throughout the region, which may
be a result of the limited information available
regarding the distribution of many species
assessed as DD. Highest numbers of DD species
󰀨
Lanka, followed by the Red Sea (Figure 7).
14
3.4 Threats

Threatened species are impacted by biological
resource use, either through direct, targeted


bycatch or habitat degradation (Figure 8). In

driver for all threatened and Near Threatened

these typically long-lived, late-maturing species
may be particularly susceptible to declines (e.g.,
Dulvy et al., 2014). The 237 threatened and
Near Threatened reef-building corals, which
represent nearly half of all the species in these
categories, are impacted by the same suite



and other problematic species, genes and


corridors.
Habitat degradation and destruction through
pollution, coastal development and other habitat

species groups assessed. These anthropogenic
activities can lead to physical damage, changes
in chemical water quality (eutrophication),
sedimentation, the introduction of pollutants,
and microbial contamination. Ultimately, habitat
loss can lead to ecosystem phase shifts in which
the dominant structuring species (i.e., corals,
seagrasses, and/or mangroves) are replaced

Phase shifts ripple through the ecosystem (Done,
1992), many causing a net loss of biodiversity as

2004).
Climate change further emerged as a major
driver of extinction risk for some taxa in some
sub-regions of the WIO. In the northwestern
WIO, climate change, aggravated by local
stressors such as coastal development, has been
implicated in the decline of coral assemblages

15

or Near Threatened that are impacted by various threats. Species are often impacted by more than one threat.
Burt et al., 2014). The Red Sea has high levels
of coral endemism (DiBattista et al., 2016), while
both regions have limited connectivity to other
parts of the WIO, and high and variable salinity

2001). Corals in these regions are vulnerable to

existing at the edge of the environmental and/


the southwestern WIO, South Africa has distinct

󰀨
This biogeography contributes to high endemism


has led to shifting distributions of commercially

ecological, and economic impacts that complicate
resource management (Sink et al., 2012).
󰀨
change, the survival of some species, such as





These taxa are likely to experience population
declines as a response to reduced habitat
󰀨

16
Spotted Seahorse (Hippocampus kuda
2.0
3.5 Research needs
Our results highlight several key research needs,
including those for habitat-forming species and
exploited species. Approaches for economic
valuation can further contribute to biodiversity
conservation.
Habitat-forming species provide valuable
ecosystem services that support both human and

resolution information is available throughout
much of the WIO on the distribution and
abundance of these species. These research
needs should be elevated within existing
research and resource management frameworks
of the respective nation-states and territories of
the Western Indian Ocean region, and by regional
resource management organizations. Mangroves,
corals, and seagrasses primarily occur in shallow
waters, and as such a substantial portion of that




mandates of Regional Fisheries Management
Organizations (RFMOs) and arrangements
such as the Southern Indian Ocean Fisheries
Agreement, have the potential to enhance and
synthesize the highly variable existing knowledge
of the distribution of habitat-forming species.
For example, previous studies have highlighted
the need for a regional approach to coral reef
mapping in the Persian Gulf (e.g., Burt et al.,

Overexploitation of target and non-target marine


and NT species. Fishes, in general, had a high
proportion of species targeted in single- and

mammals, sea turtles and reef-building corals
were negatively impacted by incidental take as


activity, there is a pronounced need for greater

fundamental biological and ecological research
at multiple scales, from municipal to regional,
to support data-driven assessments of the

metrics such as maximum size, length-frequency

󰀨

population trends is a crucial exercise that
supports resource management and conservation
programs, as well as the Red List assessment
process.

conservation by enabling the optimal allocation of
limited management resources. Loss of local or
regional biodiversity can result in a corresponding
loss in the provision of goods and services, some
of which have tangible economic value, including
reduced resilience and resistance to change,

potential, and lost recreational opportunities

Valuing these potential losses can empower
managers to divert resources towards important
and attainable biodiversity and ecosystem
services goals.
17
Malindi Fish Market, Zanzibar © G. Saluta.
3.6. Existing conservation tools
Municipal, provincial and state/territorial

environmental mandates, many of which are
focused on economic development, food security,
and poverty alleviation. Incorporating marine
biodiversity conservation goals and strategies
into existing policy and enforcing policies will
ensure continued ecosystem support for coastal
human communities, contribute to sustainable
development initiatives, and can bolster provincial

tourism.
The open ocean, or high seas, are cooperatively
managed by Regional Fisheries Management
Organizations, international organizations formed

in an area. RFMOs such as the Indian Ocean
Tuna Commission, and agreements such as the
Southern Indian Ocean Fisheries Agreement,
can implement management actions including
󰀨
gear restrictions, as well as mandates to advance
research within their respective domains.
Both management and research functions of
these bodies have the potential to advance the
marine biodiversity and habitat conservation
in the region. Additionally, more regionally
󰀨


and thereby achieve sustainable development
goals. One example of such a regional initiative is
that of the United Nations Industrial Development
Organization (UNIDO) project of the Republic of
Sudan, which is building institutional capacities
for an eco-system approach to management of

sustainable management and development of

2019).
Many WIO nations are signatories to international
environmental agreements, including the


Convention on Biological Diversity (CBD), the
Convention on Migratory Species (CMS), the
International Convention for the Regulation of
Whaling (IWC), the UN Convention on the Law
of the Sea (UNCLOS), and the UN Sustainable
Development Goals (SDGs). These agreements
have the potential to bolster marine conservation
󰀨
goals of individual nation-states, promoting
regional cooperation, drawing political and
legal frameworks for use and governance in the
region’s oceans and seas.
Marine protected areas (MPAs) are another


recognized, dedicated and managed, through
󰀨
long-term conservation of nature with associated
ecosystem services and cultural values (Dudley,

protected management of natural marine areas.
MPAs are created by delineating zones with
associated permitted and non-permitted uses
(IUCN Global Marine and Polar Programme,
2020). The countries and territories of the WIO
have designated many small, coastal protected
areas, as well as several large oceanic protected
areas, including the British Indian Ocean Territory



Africa’s recently expanded MPA network (IUCN,

cases, these protected areas have assisted
countries in meeting Aichi targets and SDGs.


18
3.7 Species conservation successes
Within the WIO various studies have investigated
󰀩󰀨
and methods. In response to the major coral
bleaching event of 1998, Frontier-Tanzania
implemented surveys to measure the recovery
of corals within and outside of the Misali Island
Marine Conservation Areas (MIMCA) (Poonian,

pressure in the protected area sustained

overgrowth and thus promote coral recovery.
An assessment of locally managed marine areas
(LMMAs) in 2014 found that, though LMMAs
protect large areas, many are under-supported
by legal structures and enforcement mechanisms
󰀨
One strong example of success in species
conservation and management in the region
comes from a Conservation Leadership
Programme (CLP) initiative. The CLP supported
the creation of a non-governmental organization
titled Community Centred Conservation or
C3. Operating in Comoros and Madagascar,
this NGO has used innovative approaches to
promote the conservation of species in the
region. C3 research on Dugong populations
was central in developing an international
protocol for rapid assessment of dugong
populations which is now used worldwide
(conservationleadershipprogramme.org accessed

further support from CLP expanded the work of
C3 to data collection for sharks and turtles in
addition to dugongs. Funding support facilitated
the employment of resource managers and eco-
guards as well as development of alternative
livelihood cooperatives. The work of C3 is

status of its target species within the Nosy Hara

hunting are now being recorded and reported.
Since the start of the project there have been
no recorded infractions within the park and
no reports of sea turtle or dugong mortality
(conservationleadershipprogramme.org accessed

Well-structured and strategically funded projects
such as this can be powerful tools for species
conservation. The above described project
focused on species of clear conservation priority

greatly from the information provided by the
conservation status report presented here. This
󰀨
their risk of extinction, as well as key information
on the threats currently driving their decline.
19
󰀨Arothron stellatus
4.1 Overview

species across diverse taxonomic groups, 473
species that are threatened or Near Threatened
with extinction at the global level, according
to the IUCN Red List Categories and Criteria.
The status of species is based on evaluations
made by a network of experts who carried out
biodiversity assessments according to the IUCN
Red List Categories and Criteria. Complete
assessments are freely available on the IUCN
Red List website (http://www.iucnredlist.org).
The conservation status of in the WIO region

to the status of the same taxonomic suite of
species assessed in other regions. For example,

of threatened species in the Western Central




2020). However, uncertainty is highest in the


regions.

threatened species such as the southern Red
Sea and along the southern coast of India that
could be explored for prioritizing conservation

taxonomic group, and recommendations for
conservation actions are suggested. The data in
each species account provide key resources for
decision-makers, policymakers, natural resource
managers, environmental planners and NGOs.
4. Conclusions and recommendations
20
Tetrosomus gibbosus
CC BY 2.0
4.2 Application of project results
The value of the Red List extends far beyond
the assignation of threat status. The Red
List, in conjunction with the data gathered to
support it, has become an increasingly powerful
tool for conservation planning, management,
monitoring, and decision making (Rodrigues et
al., 2006). These assessments are valuable both
individually, and when aggregated for analyses,
such as those that have been presented in this
report.
National governments are the institutions

conservation action and legislation (Miller et
al., 2007). Species lists generated through the
IUCN Red List process can serve as a starting
point for the generation of national Red Lists
and lists of species of conservation concern

IUCN recommends use of the IUCN Guidelines
for Application of the IUCN Red List Criteria at

2003) when adapting global assessments to the
regional or national scale.

many problems currently facing biodiversity
(Bickford et al., 2012). Individual assessments
provide peer-reviewed information that can be
used in awareness and appreciation campaigns

conservation assessment for each species,
individual IUCN Red List accounts provide
concise summaries of geographic distribution,
population status, habitat and ecology, life history,
and uses and trade for each species, alongside
relevant, cited references found predominantly

assessments can be used by protected area
managers, zoos, aquariums, retailers and
wholesalers, tour guides, educational institutions,
and science communicators to raise biodiversity
and environmental awareness among audiences,
visitors, customers and clients (Bickford et al.,
2012). They can also be used as reference
material by researchers in biodiversity, ecology

Synthesizing Red List assessments provides
a powerful means for exploring, visualizing,
and summarizing trends across space, and
across species groups, as has been done for
this report. Some species that have undergone
re-assessment are candidates for analyses of
changes in conservation status over time and in
response to conservation action as part of the
Red List Index. Global-level analyses of Red
List results across entire clades contributes
widely to our understanding of extinction risk



of species richness and endemism (Polidoro et

2018), and presented novel patterns in use and

The results of this project serve as an important
baseline from which future assessments can
be compared, assessing trends in conservation
status over meaningful timescales and thus
󰀨
measures over time.
󰀨
aggregated Red List assessments for

delineation of Key Biodiversity Areas (KBAs).
󰀨
of species composition that are either highly
vulnerable (threatened) or irreplaceable
(restricted range) and prioritize areas that will


et al., 2019). Red List assessments provide
foundational information regarding a species’
distribution, extinction risk status and plausible
threats for KBA analyses. In this regard, the
species assessments and analyses presented in
this report could inform KBA analyses for areas of
particular importance within the WIO.
21
4.3 General conservation strategies and tools
Various conservation strategies and tools are
relevant to addressing regional and global
biodiversity needs. The Red List assessments,
encompassing not only the threat status of a
species, but also the accompanying distribution,
life history, ecology, population trends, and
threat information, can and are being used to
guide resource management at multiple scales.
From assessments at a single site, such as
environmental impact assessments (Meynell,
2005) to national-scale evaluations, such as in
national development policies and legislation
and multilateral agreements (Rodrigues et
al., 2006), Red List assessments and the
associated temporal Red List Index, are essential
benchmarks.
The Red List Assessment process provides a
powerful tool for identifying knowledge gaps. For
example, despite their commercial importance,
many commercial species were assessed as

to apply the IUCN Red List criteria. Fisheries
󰀨
population information within the context of
the Red List process and are the foundation of

However, in many cases, landings are recorded
only to the family or genus level, or species are


Red List can be used as a tool to prioritize
research needs for such species.
Raising awareness of the value and vulnerability
of the WIO’s marine biodiversity among resource
users, managers, the public, politicians, and
authorities is an ongoing conservation need.
󰀨
on conservation strategies that are already
being employed at the local, national, and

Convention for the Protection, Management
and Development of the Marine and Coastal

and forum for such strategies. In collaboration
with, amongst others, the Western Indian Ocean
Marine Science Association, the South West
Indian Ocean Fisheries Commission, IUCN,
and the Convention on Biological Diversity, the
Nairobi Convention Secretariat leads initiatives
(past, current and future) such as the State of
the Coast Report, Outlooks on MPAs and Critical
Habitats, and the Strategic Action Plan for the
protection of the WIO, all of which heighten
awareness of biodiversity issues.
Strategies for raising awareness of the value
and vulnerability of the WIO’s marine biodiversity
include:

species is a species selected to act as an

habitat, issue, protected area campaign


Hosting events designed to create awareness
of resident biodiversity and among a wide
range of communities, such as national
󰀨
on regional biodiversity and existing
conservation tools and strategies.
Incorporating biodiversity topics in
educational curricula for school-aged children

Matthies et al., 2011).
Incorporating Red List Assessment
Categories of organisms on display in zoos
and aquariums (Whitehead, 1995).
Deploying social media campaigns to

conservation issues (Bickford et al., 2012).
Areas for potential improvement in the
governance of the oceans and coastal
environment in the WIO region include
addressing policy and legislative inadequacies,
increasing institutional capacities, raising

resources and mechanisms, and improving
knowledge management. Translation of
22
international agreements and commitments into
national law is heterogenous across the region.
Continuing improvements in technical capacity,

strengthening of political will and prioritization,
and reduced political instability will contribute
to regional improvements in management of

WIOMSA, 2015). WIO Threatened Species
Task Forces have been suggested as means to
mobilize capacity to deal with threatened marine

WIOMSA, 2015).
4.4 Next steps
This report includes numerous new assessments
of marine species in the Western Indian Ocean,
representing a substantial contribution to
knowledge of the distribution, population status,
habitat, ecology, conservation status, threats, and
extinction risk of marine biodiversity in the region.
Despite this substantial taxonomic coverage,
there remain species and species groups that are

assessments, in particular, are lacking.
Completing these assessments, and performing
re-assessments at regular intervals, is a valuable
exercise that contributes to characterizing the
status of regional biodiversity and the relative
impact of conservation initiatives.
󰀨
conservation in the marine environment are the

subsequent installation of marine protected area

(McLeod et al., 2009). KBAs are an iterative
and site-based methodology of identifying
where conservation measures will be most
󰀨
assessments resulting from this study are integral
to completing the KBA process. Founded on
the concepts of vulnerability and irreplaceability,
KBAs enable conservation managers to identify
places where (a) conservation is most needed
to preserve biodiversity and (b) places where
marine areas can feasibly be managed and
protected (Langhammer et al., 2007). Where

managers and other stakeholders can delineate
a network of protected areas that encompass

of connectivity between the sites, as well as
passageways and refuge for highly mobile and

󰀨
means of instituting protected areas for marine

󰀨
in establishing and maintaining small, no-take
marine protected areas (Weeks et al., 2014).
23
Doryrhamphus excisus

licensed under CC BY 2.0
Whitespotted Grouper (Epinephelus
coeruleopunctatus
by D.P. Wilson and licensed under CC BY 2.0.
The IUCN Red List of Threatened SpeciesTM

to share the knowledge gathered by its global
community of over 10,000 scientists and
conservation professionals. Training in the
application of biodiversity data sets to species
and site-based management and enforcement
activities is available through the IUCN
Conservation Planning Specialist Group, the
IUCN Species Monitoring Specialist Group, and
the IUCN World Commission on Protected Areas/

on Biodiversity and Protected Areas.
The following reference documents provide
valuable tools for using IUCN Red List
Assessments to inform area-based conservation
measures:
A Global Standard for the Identication of Key
Biodiversity Areas. Version 1.0 (2016)
Guidelines for Applying Protected Area
Management Categories (2008)
Guidelines for applying the IUCN protected
area management categories to marine
protected areas. Second edition (2019)
For more information on using the IUCN Red List
of Threatened SpeciesTM to inform conservation
planning, including KBAs and protected areas,
please reach out to the following:
IUCN Global Marine and Polar Programme
IUCN Marine Conservation Committee
World Commission on Protected Areas –
Marine Division
Species Survival Commissions (SSC)
Specialist Groups

Oceans Law and Governance Specialist
Group
24
Dhow © G. Saluta.
Chumbe Island Coral Park Nature Reserve and
Reef Sanctuary © G. Saluta




arc-minute global relief model: procedures, data
sources and analysis’. National Oceanic and
Atmospheric Administration. NOAA Technical



the conservation of marine biodiversity’. Marine
Pollution Bulletin 56 (3), 386–396.
https://doi.org/10.1016/j.marpolbul.2007.11.013

transition: Food and nutrition security implications
for the global South’. Global Food Security 3 (1),
59–66.


communication for biodiversity conservation’.
Biological Conservation 151 (1), 74–76.
https://doi.org/10.1016/j.biocon.2011.12.016


A. and I. C. F. Stewart (eds.), Oceanographic and
Biological Aspects of the Red Sea, pp. 239–265.
Basel, Switzerland: Springer Oceanography.
https://doi.org/10.1007/978-3-319-99417-8_14

󰀨

and population structure’. Australian Journal of
Ecology 23 (3), 274–279.

Muths, D., Mou-Tham, G. and Kulbicki, M. (2016).

Ocean reef fauna’. Acta Oecologica 72, 72–86.
https://doi.org/10.1016/j.actao.2015.10.009


importance of culture and local contexts’. Oryx 36
(2), 189–195.

of marine biogeographic provinces with reference to
ournal of Biogeography 39 (1),
12–30.
https://doi.org/10.1111/j.1365-2699.2011.02613.x



the Gulf’. Marine Pollution Bulletin 105 (2), 480–
488. https://doi.org/10.1016/j.marpolbul.2015.11.033


science in urgent need of protection’. Ocean
Challenge 20, 49–56.

Bennun, L.A., Stuart, S.N., Akcakaya, H.R., Hilton-

Indices to measure progress towards the 2010
target and beyond’. Philosophical Transactions of
the Royal Society B 360, 255–268.
https://doi.org/10.1098/rstb.2004.1583

U. (1997). FAO Species Identication Field Guide
for Fishery Purposes. The Living Marine Resources
of Kuwait, Eastern Saudi Arabia, Bahrain, Qatar,
and the United Arab Emirates. Rome, Italy: Food
and Agriculture Organization of the United Nations.

building corals face extinction from climate change
and local impacts’. Science 321, 560–563. https://
doi.org/ 10.1126/science.1159196

Kearney, K., Watson, R. and Pauly, D. (2009).

climate change scenarios’. Fish and Fisheries 10,
235–251.



Oshore sheries of the
Southwest Indian Ocean: their status and the impact
on vulnerable species. Special Publication No. 10.
Durban, South Africa: South African Association for
Marine Biological Research.

of extinction of iconic and dominant components

PLoS ONE 7 (7), e39825. https://doi.org/10.1371/
journal.pone.0039825
Conservation Leadership Programme,
UK. (2020). Available at: http://www.
conservationleadershipprogramme.org/news/
saving-species-western-indian-ocean/
References
25

ecosystem services and natural capital’. Nature
387, 253–260. https://doi.org/10.1038/387253a0

󰀨
L. (eds.) (2019). Guidelines for Applying the
IUCN Protected Area Management Categories to
Marine Protected Areas. Second edition. Gland,
Switzerland: IUCN.
https://portals.iucn.org/library/node/48887
de Groot, R.S., Alkemade, R., Braat, L., Hein, L.

the concept of ecosystem services and values in
landscape planning, management and decision
making’. Ecological Complexity 7 (3), 260–272.
https://doi.org/10.1016/j.ecocom.2009.10.006

contemporary patterns of endemism for shallow
water reef fauna in the Red Sea’. Journal of
Biogeography 43 (3), 423–439.
https://doi.org/10.1111/jbi.12649


Hydrobiologia 247, 121–132.
https://doi.org/10.1007/978-94-017-3288-8_13
Dudley, N. (ed.) (2008). Guidelines for Applying
Protected Area Management Categories. Gland,
Switzerland: IUCN. x + 86pp.
https://doi.org/10.2305/IUCN.CH.2008.PAPS.2.en

conservation of the world’s sharks and rays’. eLife
3: e00590. https://doi.org/10.7554/eLife.00590.001


of marine biological diversity’. Aquatic Conservation
18 (6), 969–983.
https://doi.org/10.1038/nature13022

outcomes depend on marine protected areas with
Nature 506, 216–220.

as site conservation targets’. BioScience 54
(12), 1110–1118. https://doi.org/10.1641/0006-



analysis of their status in the Southwest Indian

Oshore sheries of the Southwest Indian Ocean:
their status and the impact on vulnerable species,
pp.19-65. Oceanographic Research Institute,
Special Publication, 10. 448pp.
Fischer, W. and G. Bianchi (eds.) (1984). FAO
species identication sheets for shery purposes.
Western Indian Ocean (Fishing Area 51). Prepared
and printed with the support of the Danish
International Development Agency (DANIDA).
Rome, Italy: FAO. Vol. 1–6.


Species, References. http://researcharchive.
calacademy.org/research/ichthyology/catalog/


specialisation and overlap in a guild of coral reef
Marine Ecology
Progress Series 305, 163–175.
https://doi.org/10.3354/meps305163
Gärdenfors, U., Hilton-Taylor, C., Mace, G.M. and

Red list criteria at regional levels’. Conservation
Biology 15, 1206–1212.


Gulf of Aqaba, endemism and Lessepsian migrants’.
Zootaxa 4509 (1), 1–215

the Western Indian Ocean’. Western Indian Ocean
Journal of Marine Science 5 (1), 55–70.
https://doi.org/10.4314/wiojms.v5i1.28497



and community structure with implications for
management’. Marine Pollution Bulletin 105, 515–
523. https://doi.org/10.1016/j.marpolbul.2015.10.005

The RV Dr. Fridtjof Nansen in the Western Indian
Ocean: Voyages of marine research and capacity
development. Rome, Italy: FAO.

evaluation of threatened species categorization
systems used on the American continent’.
Conservation Biology 20 (1), 14–27.
https://doi.org/10.1111/j.1523-1739.2006.00352.x
Eviota
dalyi, a new dwarfgoby from the Amirante Islands,
Seychelles (Teleostei: Gobiidae)’. Journal of the
Ocean Science Foundation 33, 9–15.
26


Threatened by Shrimp Aquaculture in Sri Lanka’.
Environmental Management 36, 535–550.
Halpern, B. S., S. Walbridge, K. A. Selkoe, C. V.


human impact on marine ecosystems’. Science 319,
948–952.
https://doi.org/10.1126/science.1149345

changes in cumulative human impacts on the
world/’s ocean’. Nature Communications 6, 1–7.
https://doi.org/10.1038/ncomms8615

Coastal Fishes of the
Western Indian Ocean. Grahamstown, South Africa:
South African Institute for Aquatic Biodiversity.
󰀨
and the IUCN Red List’. Endangered Species
Research 6 (2), 113–125.
https://doi.org/10.3354/esr00087
ICMBio/MMA (2018). Livro Vermelho da Fauna
Brasileira Ameaçada de Extinção: Volume I / -- 1st.
ed. Brasília, DF. 492 p.
International Union for Conservation of Nature
(IUCN) (2003). Guidelines for Application of IUCN
Red list Criteria at Regional Levels: Version
3.0. Gland, Switzerland: IUCN Species Survival
Commission.
https://portals.iucn.org/library/node/8255
IUCN (2004). Managing Marine Protected Areas:
A Toolkit for the Western Indian Ocean. Nairobi,

https://portals.iucn.org/library/node/8643
IUCN (2012). IUCN Red List Categories and
Criteria: Version 3.1. Second edition. Gland,
Switzerland and Cambridge, UK: IUCN.
https://portals.iucn.org/library/node/10315
IUCN (2016). Guidelines for appropriate uses of
IUCN Red List Data. Incorporating as Annexes,
the 1) Guidelines for Reporting on the Proportion


Guidelines for the Appropriate Use of the IUCN Red
List by Business (ver. 1.0). Version 3.0. Adopted by
the IUCN Red List Committee.
IUCN Global Marine and Polar Programme (2020).
Marine Protected Areas. Available at:
https://www.iucn.org/theme/marine-and-polar/our-
work/marine-protected-areas

Threats and extinction risk of the sharks, rays and
chimaeras of the Arabian Sea and adjacent waters’.
Fish and Fisheries 19 (6), 1043–1062.
https://doi.org/10.1111/faf.12311

Fisheries in Tanzania 2002’. Ambio 31 (7–8), 518–
536. https://doi.org/10.1579/0044-7447-31.7.518


biodiversity in marine reserves’. Proceedings of the
National Academy of Sciences of the United States
of America 101 (21), 8251–8253.
https://doi.org/10.1073/pnas.0401277101

biodiversity in the Indian Ocean: The known,
unknown and unknowable’. Indian Journal of Marine
Science 34, 11–26.

to species of conservation concern’. Conservation
Biology 18, 1636–1644. https://doi.org/10.1111/
j.1523-1739.2004.00464.x



richness across island and mainland regions’.
Proceedings of the National Academy of Science of
the United States of America 106 (23), 9322–9327.
https://doi.org/10.1073/pnas.0810306106
Langhammer et al. (2007). Identication and gap
analysis of key biodiversity areas: targets for
comprehensive protected area systems. Gland,
Switzerland: IUCN.
Linardich, C., Ralph, G.M., Robertson, D.R.,
Harwell, H., Polidoro, B.A., Lindeman, K.C.


Greater Caribbean and Gulf of Mexico’. Aquatic
Conservation: Marine and Freshwater Research 29
(1), 85–101. https://doi.org/10.1002/aqc.2959
Lindemann-Matthies, P., Constantinou, C., Lehnert,


of preservice teachers to implement biodiversity
education in primary schools—Four comparative
International Journal of
Science Education 33 (16), pp.2247–2273.
https://doi.org/10.1080/09500693.2010.547534
27

C., Akcakaya, H.R., Leader-Williams, N., Milner-


Threatened Species’. Conservation Biology 22 (6),
1424–1442.
https://doi.org/10.1111/j.1523-1739.2008.01044.x


to address the impacts of climate change’. Frontiers
in Ecology and the Environment 7 (7), 362–370.
https://doi.org/10.1890/070211


environmental aspects’. Progress in Oceanography
60 (2-4), 263–279.
https://doi.org/10.1016/j.pocean.2004.02.014

process as a basis for assessing biodiversity threats
and impacts in environmental impact assessment’.
Impact Assessment and Project Appraisal 23, 65–
72. https://doi.org/10.3152/147154605781765689


Gärdenfors, U.L.F., Keller, V., Molur, S., Walker,

species listing based on IUCN criteria and regional
guidelines: current status and future perspectives’.
Conservation Biology 21 (3), 684–696.
https://doi.org/10.1111/j.1523-1739.2007.00656.x


Sustainable Development’. Environmental Values 6
(2), 213–233.
https://doi.org/10.3197/096327197776679158


Fish and Fisheries 9 (3),
261–285.
https://doi.org/10.1111/j.1467-2979.2008.00281.x
Fishes of the World, 4th

Inc. https://doi.org/10.1002/div.5366

of Western Indian Ocean reef-building corals’. PLoS
ONE 7 (9), e45013.
https://doi.org/10.1371/journal.pone.0045013
Obura, D., et al. (2017). Reviving the Western
Indian Ocean Economy: Actions for a Sustainable
Future. Gland, Switzerland: WWF International.

biodiversity to sustain marine ecosystem services’.
Frontiers in Ecology and the Environment 7, 204–
211. https://doi.org/10.1890/070135


Global Concern’. PLoS ONE 5 (4): e10095.
https://doi.org/10.1371/journal.pone.0010095

area management on the status of coral reefs at
Misali Island, Tanzania following the 1998 bleaching
event in the western Indian Ocean’. African Journal
of Ecology 46 (4), 471–478. https://doi.org/10.1111/
j.1365-2028.2007.00873.x


Susceptibility among Corals Subject to Ocean
Warming and Recurrent Bleaching in Moorea,
French Polynesia’. PLoS ONE 8 (7), e70443.
https://doi.org/10.1371/journal.pone.0070443


of being valuable: predictors of extinction risk in
marine invertebrates exploited as luxury seafood’.
Proceedings of the Royal Society B 281, 2013329.
https://doi.org/10.1098/rspb.2013.3296
Glimpses of the Indian Ocean.
Hyderabad, India: Universities Press Ltd. 206 p.

by frequent disturbance: examples from the
Arabian Gulf, South Africa, and the Cayman
Islands’. Palaeogeography, Palaeoclimatology,
Palaeoecology 175, 79–101.

Richmond, M.D. (ed.) (1997). A Guide to the
Seashores of Eastern Africa and the Western Indian
Ocean Islands. Sida/Department for Research


of the western Indian Ocean and its biogeography:
How much do we know?’. In: M.D. Richmond and
Marine science development
in Tanzania and eastern Africa. Proceedings of
the 20th Anniversary Conference on Advances in
Marine Science in Tanzania (IMS/WIOMSA), pp.
241–261.

hotspots and conservation priorities for tropical
reefs’. Science 295 (5558), 1280–1284.
https://doi.org/10.1126/science.1067728
28

for humanity’. Nature 461, 472–475.
https://doi.org/10.1038/461472a
󰀨

managed marine areas (LMMAs) in the Western
Indian Ocean’. PLoS ONE 9 (7), e103000. https://
doi.org/10.1371/journal.pone.0103000

󰀨
IUCN Red List for conservation’. Trends in Ecology
and Evolution 21 (2), 71–76.
https://doi.org/10.1016/j.tree.2005.10.010
Saurida
(Pisces: Synodontidae) from the Mascarene
Plateau, Western Indian Ocean’. Zootaxa 3947(3),
440–446.
https://doi.org/10.11646/zootaxa.3947.3.10

species of Nemipterus (Pisces: Nemipteridae)
from the Western Indian Ocean’. Zootaxa 3630 (1),
191–197.
https://doi.org/10.11646/zootaxa.3630.1.9

sustainable ecological management of marine
communities of the Persian Gulf’. Ambio 40, 4–17.
https://doi.org/10.1007/s13280-010-0092-6
Samoilys, M., et al. (2015). Resilience of Coastal
Systems and their Human Partners in the Western
Indian Ocean. 


in decline’. Marine Pollution Bulletin 60, 13–38.
https://doi.org/10.1016/j.marpolbul.2009.10.017
Sheppard, C., Price, A. and Roberts, C. (1992).
Marine Ecology of the Arabian Region: Patterns
and Processes in Extreme Tropical Environments.
London: Academic Press.
https://doi.org/10.1007/978-94-007-3008-3_16

concerns for the future of Gulf coral reefs’. In: B.M.
Coral Reefs of the Gulf,
pp. 349–373. Dordrecht, the Netherlands: Springer.

Assessment of the World’s Seagrass Species’.
Biological Conservation 144, 1961–1971. https://doi.
org/10.1016/j.biocon.2011.04.010
Sink, K., et al. (2012). National Biodiversity
Assessment 2011: Technical Report. Volume 4:
Marine and Coastal Component. Pretoria, South
Africa: South African National Biodiversity Institute,
pp 325.
Skowno, A.L., et al. (2019). National Biodiversity
Assessment 2018: The status of South Africa’s
ecosystems and biodiversity. Synthesis Report.
Pretoria: South African National Biodiversity
Institute, an entity of the Department of

Smith, M.M. and Heemstra, P.C. (1986). Smith’s
Sea Fishes. Grahamstown, South Africa: Springer-
Verlag.


󰀨
(Tetradontiformes: Tetradontidae)’. Global Ecology
and Conservation 14, e00388.
https://doi.org/10.1016/j.gecco.2018.e00388
Tea, Y.K., Pinheiro, H.T., Shepherd, B. and Rocha,
Cirrhilabrus wakanda, a new species
of fairy wrasse from mesophotic ecosystems of
Zanzibar, Tanzania, Africa (Teleostei, Labridae)’.
Zookeys 863, 85–96.
https://doi.org/10.3897/zookeys.863.35580



Biological Conservation 92 (1), pp.59–72.
https://doi.org/10.1016/S0006-3207(99)00063-4

Situation and Prospects. Statistical Annex. https://
www.un.org/development/desa/dpad/wp-content/


Convention and Western Indian Ocean Marine
Science Association (WIOMSA) (2015). The
Regional State of the Coast Report: Western Indian
Ocean

Database on Protected Areas (WDPA). Cambridge,

Protected Areas. https://www.protectedplanet.net/
en/thematic-areas/wdpa
UN Industrial Development Organization (UNIDO)
(2019). Building institutional capacities for an eco-
system approach to management of the marine
shery in the Red Sea State (Phase II). https://open.
unido.org/projects/SD/projects/170230



29
N. Karenyi (eds), South African National Biodiversity
Assessment 2018. Technical Report Volume 4:
Marine Realm, chapter 9. Pretoria, South Africa:
South African National Biodiversity Institute.

Mwatha, G., Afonso, P.S. and Boulle, D. (2005).

Ocean: their diversity and status, a preliminary
assessment’. Philosophical Transactions of the
Royal Society of London A 363, 263–284.
https://doi.org/10.1098/rsta.2004.1492

biodiversity meaningful through environmental
education’. International Journal of Science
Education 24 (11), 1143–1156.
https://doi.org/10.1080/09500690210134839
󰀨

of zooxanthellate Scleractinia’. Frontiers in Marine
Science 1, article 81. https://doi.org/10.3389/
fmars.2014.00081
Vidyasagaran, K. and Madhusoodanan, V.K. (2014).

west coast of Kerala, India’. Journal of Biodiversity
and Environmental Sciences 4 (5), 38–45.

knowledge on threatened amphibian species in
Peru’. Tropical Conservation Science 1 (4), 376–
396. https://doi.org/10.1177/194008290800100406
Brachirus sayaensis, a New
Soleid Species (Soleidae: Pleuronectiformes) from
Saya de Malha Bank’. Journal of Ichthyology 59,
418–424.
https://doi.org/10.1134/S0032945219030202
Wafar, M., Venkataraman, K., Ingole, B., Khan, S.A.

Coastal and Marine Biodiversity of Indian Ocean
Countries’. PLoS ONE 6 (1), e14613.
https://doi.org/10.1371/journal.pone.0014613

area networks in the Coral Triangle: good practices
for expanding the Coral Triangle Marine Protected
Area System’. Coastal Management 42 (2), 183–
205. https://doi.org/10.1080/08920753.2014.877768

species and habitats: Biodiversity education and
the role of zoos’. Biodiversity & Conservation 4 (6),
664–670. https://doi.org/10.1007/BF00222521
Whitty, T.S., Davis, P., Poonian, C. and Leandre, I.

󰀨

Madagascar’. Proceedings of the World Small Scale
Fisheries Congress, Bangkok, Thailand. pp. 18-22.


and socioeconomic impacts of 1998 coral mortality

warning of future change?’. Ambio 28 (2), 188–196.
󰀨


ecosystem services’. Science 3 (14), 787–790.
https://doi.org/10.1126/science.1132294
Note: for the extensive literature used to compile
each species assessment, please see each species
account on the IUCN Red List (www.iucnredlist.org).
30
Appendix: Expert participants
31

󰀩
Participant Name A󰀩liation Country
󰀨 Old Dominion University/IUCN USA
Philippe Borsa  France
Robert Bullock The Deep Aquarium/IUCN 
Kent Carpenter Old Dominion University/IUCN USA
Fabio Di Dario  Brazil
 Institute of Marine Sciences, University of Dar es Salaam Tanzania
Moazzam Khan WWF-Pakistan Pakistan
Helen Larson Museum and Art Gallery of the Northern Territory Australia
Keiichi Matsuura National Museum of Nature and Science 
Hiroyuki Motomura The Kagoshima University Museum 
Clay Obota Coastal Oceans Research and Development - Indian Ocean (CORDIO) Kenya
Beth Polidoro Arizona State University/IUCN USA
Gina Ralph Old Dominion University/IUCN USA
William Smith-Vaniz Florida Museum of Natural History, University of Florida USA
Saleh Yahya Institute of Marine Sciences, University of Dar es Salaam Tanzania
Workshop group photo in Zanzibar © G. Ralph.
32

󰀩
Participant Name A󰀩liation Country
Farid Saud Hamed Al
Abdali
 Oman
  Oman
Asma Al Bulushi  Oman
Bader Al Buwaiqi  Oman
Abdullah Sulaiman
Musbah Al Kindi
 Oman
Aisha Ambuali  Oman
Philippe Borsa  France
Kent Carpenter Old Dominion University/IUCN USA
Anesh Govender  Oman
Helen Larson  Australia
Christi Linardich Old Dominion University/IUCN USA
Beth Polidoro Arizona State University/IUCN USA
Gina Ralph Old Dominion University/IUCN USA
Barry Russell  Australia
Alan Williams  Australia
Workshop group photo in Muscat © G. Ralph.
33

󰀩
Participant Name A󰀩liation Country
Robert Bullock The Deep Aquarium/IUCN 
 South African Association for Marine Biological Research Oceanographic
Research Institute South Africa
Sean Fennessy South African Association for Marine Biological Research Oceanographic
Research Institute South Africa
Catarina Fonseca Oceanario de Lisboa/IUCN Portugal
Claire Gorman Old Dominion University/IUCN USA
Hans Ho Institute of Marine Biology, National Dong Hwa University Taiwan
Wouter Holleman South African Institute for Aquatic Biodiversity South Africa
Christi Linardich Old Dominion University/IUCN USA
Patroba Matiku Tanzania Fisheries Research Institute Tanzania
Claque Maunde National Institute of Fisheries Research Mozambique
Thomas Munroe U.S. National Marine Fisheries Service/Smithsonian Institution USA
Rekha Nair India Central Marine Fisheries Research Institute India
Gina Ralph Old Dominion University/IUCN USA
Barry Russell  Australia
Yonela Sithole South African Institute for Aquatic Biodiversity South Africa
Franz Uiblein Institute of Marine Research Norway
Steven Weerts  South Africa
Alan Williams  Australia
Workshop group photo in Durban © G. Ralph
IUCN
Rue Mauverney 26
CH 1196 Gland
Switzerland
Tel: +41 22 999 0000
Fax: + 41 22 999 0002
www.iucn.org/redlist
www.iucnredlist.org
... Patterns of coral reef fish diversity and their drivers are increasingly being understood at large spatial For example, compiled presence/absence observations of species are used to create polygon distribution maps that estimate total species diversity (Selig et al. 2014, Jenkins & Van Houtan 2016, Bullock et al. 2021. Species diversity patterns arising from this common method produce distributions based on extrapolations across large areas. ...
... Regional currents that transport larvae have been shown to facilitate inter-reef connectivity in the north (Crochelet et al. 2016, Maina et al. 2020). Previous predictions for fish have been at a coarse scale and not clearly associated with environmental conditions (Jenkins & Van Houtan 2016, Bullock et al. 2021. Some patterns here suggest that environmental factors are more important than ecoregion, biogeographic distance, size, and connectivity metrics. ...
Article
Full-text available
Predicting and mapping coral reef diversity at moderate scales can assist spatial planning and prioritizing conservation activities. We made coarse-scale (6.25 km ² ) predictive models for numbers of coral reef fish species and community composition starting with a spatially complete database of 70 environmental variables available for 7039 mapped reef cells in the Western Indian Ocean. An ensemble model was created from a process of variable elimination and selectivity to make the best predictions irrespective of human influences. This best model was compared to models using preselected variables commonly used to evaluate climate change and human fishing and water quality influences. Many variables (~27) contributed to the best number of species and community composition models, but local variables of biomass, depth, and retention connectivity were dominant predictors. The key human-influenced variables included fish biomass and distance to human populations, with weaker associations with sediments and nutrients. Climate-influenced variables were generally weaker and included median sea surface temperature (SST) with contributions in declining order from SST kurtosis, bimodality, excess summer heat, SST skewness, SST rate of rise, and coral cover. Community composition variability was best explained by 2 dominant community richness axes of damselfishes-angelfishes and butterflyfishes-parrotfishes. Numbers of damselfish-angelfish species were ecologically separated by depth, and damselfishes declined with increasing depth, median temperature, cumulative excess heat, rate of temperature rise, and chronic temperature stresses. Species of butterflyfish-parrotfish separated by median temperature, and butterflyfish numbers declined with increasing temperature, chronic and acute temperature variability, and the rate of temperature rise. Several fish diversity hotspots were found in the East African Coastal Current Ecoregion centered in Tanzania, followed by Mayotte, southern Kenya, and northern Mozambique. If biomass can be maintained, the broad distributions of species combined with compensatory community responses should maintain high diversity and ecological resilience to climate change and other human stressors.
... The lower estimate assumed no DD and NE species were classified as ER [(CR + EN + VU + NT)/(total assessed)], and the upper estimate assumed all DD and NE species were classified as ER [(CR + EN + VU + NT + DD + NE)/(total assessed)]. The best estimate represented the total percentage of ER species if the same proportion of DD and NE species are Threatened or Near Threatened [(CR + EN + VU + NT)/(total assessed − DD − NE)] as in [32,33]. ...
... Findings here highlight that sharks and rays comprise the majority of ER species using the D'Arros and St Joseph site, with all sharks and ray species being listed as ER. Comparatively, across the Western Indian Ocean, a best estimate of 43% of the 243 species of occurring sharks and rays were deemed threatened [33]. This suggests that D'Arros and St Joseph represent an important area for globally threatened sharks and rays, and the site could be a good candidate for inclusion in discrete areas of significance, such as Key Biodiversity Areas [35], or the Important Shark and Ray Areas currently in development (ISRAs: sharkrayareas.org/isra). ...
Article
Full-text available
Global Red List assessments are powerful tools for informing large-scale conservation decision-making processes, however, they can also be used to inform more localised research and conservation priorities. Here, a conservation status assessment was conducted for the marine vertebrate biodiversity of two recently designated marine protected areas in the Republic of Seychelles. International Union for Conservation of Nature (IUCN) Red List assessments were compiled and trends in data analysed for the 524 species recorded locally. Findings suggest that 5.5–23.1% of all marine vertebrate biodiversity at the site is threatened or near-threatened with extinction (combined as ‘elevated risk’), and highlights sharks and rays as contributing two thirds (67.9%) to the ‘elevated risk’ biodiversity of the site. Fishing activities constitute the largest threat to every ‘elevated risk’ species using the site, with sharks and rays being most impacted. Species richness analysis across major habitat types evidence the high value of coral reef areas to almost all species and the importance of adjacent deep-water areas for ‘elevated risk’ species. Theoretical national assessments showed that the majority of globally ER species remained in the same Red List category in their respective national assessment. This study demonstrates the value of global Red List data for optimising research efforts and conservation practices on a localised scale and for informing the design and zonation of marine protected areas.
... The number of species is now evaluated at 65, with 50 species of sharks and 15 species of batoids, though uncertainties remain on the taxo- nomic identification and the real presence of some species. Similarly, a recent assessment of the marine biodiversity of the Western Indian Ocean estimated 264 sharks and rays [41], which is more than the 188 species recorded in an earlier review [42]. This difference in the number of species highlights that accurately evaluating the marine biodiversity of a region is challenging, even though it is fundamental to supporting effective fisheries management and implementing efficient conservation plans for threatened species. ...
Article
Full-text available
Elasmobranchs are declining worldwide due to overfishing. In developing countries and island states in tropical regions, small-scale and recreational fisheries can significantly impact the dynamics of neritic species. We investigated elasmobranch diversity at Reunion Island, a marine biodiversity hotspot in the Western Indian Ocean. Combining information from the literature, catches from the local shark control program, results from a survey of local recreational fishing, and through barcoding of some specimens, we updated the list of elasmobranchs to 65 species. However, uncertainties remain about the actual presence of some species, such as the three sawfish species. Results highlight the disappearance of most coral reef-associated species, as already suspected. Results also suggest that local populations of scalloped hammerhead shark (Sphyrna lewini) and bottlenose wedgefish (Rhynchobatus australiae) seem healthy, in contrast with their decline in the region. For some species, such as bull sharks (Carcharhinus leucas) and scalloped hammerhead sharks, Reunion Island is a site of reproduction, and as such, the species are exploited at both juvenile and adult stages, which likely increases their vulnerability. In the context of global elasmobranch decline, it is urgent to clarify the conservation status and evaluate the degree of isolation of local populations to identify research and conservation priorities.
Book
Full-text available
This book is about the preservation of biodiversity in the oceans and new solutions for the protection of these important marine creatures and the commitments of governments at the international level
Book
Full-text available
this book is about pritction of marine bio diversity in high seas and explain about giverments commitments in high seas emphasize on sustainable development.
Article
Full-text available
Sea turtles are essential to the health of marine ecosystems, yet nearly 90% are threatened with extinction. The unsustainable consumption of sea turtles contributes to their global decline. Because sea turtle meat is also high in heavy metals, the monitoring of sea turtle consumption is a priority for both marine conservation and public health. Despite this, sea turtle consumption was understudied along Madagascar’s eastern coastline. We used structured interviews (collected over nine years) in northeastern Madagascar to study the rural consumption of sea turtles and other marine megafauna (including dolphins, whales, and dugongs). Sea turtle consumption is increasing in the southwest Indian Ocean. Over 80% of households ate a mean of 1.47 kg of sea turtle meat per year over the prior decade. The vast majority of sea turtle meat was purchased. Households which were more financially and nutritionally secure ate significantly more sea turtle meat. Sea turtle meat did not provide a significant source of nutrients to insecure households. Thus, its elimination from the diet would be unlikely to economically or nutritionally harm consumers. In fact, sea turtle meat contributed significantly to heavy metal burdens within communities and reducing consumption is a key step toward ensuring both adequate public and environmental health. Social marketing campaigns on the content and effects of heavy metals in sea turtle meat paired with increased heavy metal testing of children and pregnant women, may benefit both local communities and marine conservation.
Article
Full-text available
Cirrhilabrus wakanda sp. nov. is described on the basis of the holotype and four paratypes collected between 50 and 80m depth over low-complexity reef and rubble bottoms at the east coast of Zanzibar, Tanzania, Africa. The new species belongs to a group of fairy wrasses from the western Indian Ocean, sharing a combination of characters that include: short pelvic fins (not or barely reaching anal-fin origin); relatively unmarked dorsal and anal fins; males with a strongly lanceolate caudal fin (except in C. rubrisquamis); both sexes with a pair of prominent facial stripes above and below the orbit; and both sexes with prominent purple scales and osseus elements that persist, and stain purple, respectively, even in preservation. This group of fairy wrasse is part of a larger complex that includes related species from the western Pacific Ocean. In addition to meristic and morphometric comparisons, we also compare mitochondrial DNA sequence data to the aforementioned, putatively related species.
Article
Full-text available
Two soleid specimens from Saya de Malha Bank are described as Brachirus sayaensis sp. nov. It is distinguished from other soleid species by the combination of the following characters: caudal fin joined to dorsal and anal fins, pectoral fins very short, but present, total number of vertebrae 45-46; first ray of dorsal fin not enlarged and free; scales ctenoid on both sides of body; body slightly elongate, no bony process on snout; eyes separated by an interorbital space; opercular membrane free from the body; no labial fringes; pel-vic fin of eyed side free, not joined to anal fin; anterior nostril of ocular side does not reach anterior margin of lower eye, dorsal fin rays 77, anal fin rays 61-62, lateral line scales 97-105, color of ocular side in alcohol light brownish, no stripes and spots.
Chapter
Full-text available
The Red Sea is characterised by a unique composition of species of fishes which, based on unpublished data of the present authors, currently consists of 1166 species from 159 families whose habitats range from shallow waters to the deep sea. There is a total of 1120 species in coastal waters of the Red Sea recorded within an overall depth range 0–200 m; among them, 165 species are exclusively endemics to the Red Sea, whilst another 51 species are restricted to the Red Sea and Gulf of Aden only, and 22 species living at depths greater than 200 m are endemic. As the westernmost peripheral area of the Indo-West Pacific region, the Red Sea is at the opposite end of the distributions of many widespread coral reef organisms that range to the easternmost regions, such as the Hawaiian Islands, Easter Island, and the Marquesas Islands. It is noted that these areas exhibit high percentages of endemism among coastal fishes. The Hawaiian archipelago has 30.7% of its fishes as endemic species; Easter Island has 21.7%, the Red Sea 14.7% (19.3% when combined with the Gulf of Aden), and the Marquesas Islands have 13.7% endemic fishes. The Red Sea is 2250 km in length and it is very deep, with an average depth of 490 m, and a maximum depth of 3040 m. As expected, the fish fauna is far from homogeneous. The most divergent sector is the Gulf of Aqaba. We have noted that its entrance to the rest of the Red Sea is shallow. It has a maximum width of only 24 km, but a maximum depth of 1850 m. The shore drops off quickly to deep water. The prevailing cross wind creates upwelling, resulting in surface sea temperature at least as low as 21 ℃. Twenty-two of 46 species of Red Sea fishes living at depths greater than 200 m in the Red Sea are endemic (48% endemism). The Gulf of Aqaba has 22 endemic coastal species of fishes and eight endemic deep-dwelling species. By contrast, the neighboring Gulf of Suez, with extensive sand flats and a maximum depth of 70 m, has only seven endemic species of fishes. Of the 165 endemic Red Sea species of fishes, only two are elasmobranchs. Twenty-three families of Red Sea fishes have more than 20% of endemic species with the highest rates of endemism occurring among the Pseudochromidae, Schindleriidae (83.3% and 100% respectively) and the family Gobiidae with the greatest number of endemic species (36 of 139 recorded species). A brief summary of the history of scientific research on Red Sea fishes is provided together with complete lists of endemic species for (i) the entire Red Sea (separately for coastal and deep-dwelling fishes); (ii) the Red Sea combined with the Gulf of Aden; (iii) the Gulf of Aqaba and the Gulf of Suez; and (iv) Lessepsian migrants. Ongoing research is likely to reveal additional endemic species in the region.
Article
Full-text available
The extinction risk of sharks, rays and chimaeras is higher than that for most other vertebrates due to low intrinsic population growth rates of many species and the fishing intensity they face. The Arabian Sea and adjacent waters border some of the most important chondrichthyan fishing and trading nations globally, yet there has been no previous attempt to assess the conservation status of species occurring here. Using IUCN Red List of Threatened Species Categories and Criteria and their guidelines for application at the regional level, we present the first assessment of extinction risk for 153 species of sharks, rays and chimaeras. Results indicate that this region, home to 15% of described chondrichthyans including 30 endemic species, has some of the most threatened chondrichthyan populations in the world. Seventy-eight species (50.9%) were assessed as threatened (Critically Endangered, Endangered or Vulnerable), and 27 species (17.6%) as Near Threatened. Twenty-nine species (19%) were Data Deficient with insufficient information to assess their status. Chondrichthyan populations have significantly declined due to largely uncontrolled and unregulated fisheries combined with habitat degradation. Further, there is limited political will and national and regional capacities to assess, manage, conserve or rebuild stocks. Outside the few deepsea locations that are lightly exploited, the prognosis for the recovery of most species is poor in the near-absence of management. Concerted national and regional management measures are urgently needed to ensure extinctions are avoided, the sustainability of more productive species is secured, and to avoid the continued thinning of the regional food security portfolio.
Article
Full-text available
Puffers are biologically and ecologically fascinating fishes best known for their unique morphology and arsenal of defenses including inflation and bioaccumulation of deadly neurotoxins. These fishes are also commercially, culturally, and ecologically important in many regions. One-hundred-and-fifty-one species of marine puffers were assessed against the International Union for Conservation of Nature (IUCN) Red List Criteria at a 2011 workshop held in Xiamen, China. Here we present the first comprehensive review of puffer geographic and depth distribution, use and trade, and habitats and ecology and a summary of the global conservation status of marine puffers, determined by applying the International Union for Conservation of Nature (IUCN) Red List Criteria. The majority (77%) of puffers were assessed as Least Concern, 15% were Data Deficient, and 8% were threatened (Critically Endangered, Endangered or Vulnerable) or Near Threatened. Of the threatened species, the majority are limited-ranging habitat specialists which are primarily affected by habitat loss due to climate change and coastal development. However, one threatened puffer (Takifugu chinensis – CR) and four Near Threatened puffers, also in the genus Takifugu (which contains 24 species total), are wide-ranging habitat generalists which are commercially targeted in the international puffer trade. A disproportionate number of species of conservation concern are found along the coast of eastern Asia, from Japan to the South China Sea, with the highest concentration in the East China Sea. Better management of fishing and other conservation efforts are needed for commercially fished Takifugu species in this region. Taxonomic issues within the Tetraodontidae confound accurate reporting and produce a lack of resolution in species distributions. Resolution of taxonomy will enable more accurate assessment of the conservation status of many Data Deficient puffers.
Book
Available online under http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp
Article
The current checklist provides for each species of the Red Sea its records in the Gulf of Suez, Gulf of Aqaba, Red Sea main basin and its general distribution.This new checklist of Red Sea fishes enumerates 1207 species, representing 164 families. Of these, 797 species were recorded from the Gulf of Aqaba and 339 from the Gulf of Suez. The number of species from the Gulf of Suez is evidently lower than the actual number not including 27 Lessepsian (Red Sea) migrants to the Mediterranean that most likely occur in the Gulf. The current list includes 73 species that were newly described for science since the last checklist of 2010. The most specious Osteichthyes families are: Gobiidae (134 species), Labridae (66), Apogonidae (59), Serranidae (including Anthiadinae) (44), Blenniidae (42), Carangidae (38), Muraenidae (36), Pomacentridae (35), Syngnathidae (34), Scorpaenidae (24) and Lutjanidae (23). Among the families of Chondrichthyes, the most specious families are the Carcharhinidae (18 species) and Dasyatidae (11). The total number of endemic species in the Red Sea is 174 species, of these, 34 species are endemic to the Gulf of Aqaba and 8 to the Gulf of Suez.