Technical ReportPDF Available

Eastern Atlantic & Mediterranean Angel Shark Conservation Strategy

Authors:
  • The Shark Trust

Abstract and Figures

The Eastern Atlantic & Mediterranean Angel Shark Conservation Strategy has been developed to act as a catalyst for conservation action for the three Critically Endangered angel sharks found in these regions - the Angelshark (Squatina squatina), Sawback Angelshark (S.aculeata), and Smoothback Angelshark (S. oculata).
Content may be subject to copyright.
Eastern Atlantic and Mediterranean
Angel Shark Conservation Strategy
Species background
Angel sharks* rank as the second most threatened
family of elasmobranch (sharks, skates and rays) after
sawshes1. Characteristics linking the two families
include their body shape and preferred habitat, as both
are large, at-bodied coastal species.
The family Squatinidae contains at least 23 species, half
of which are listed as threatened (Critically Endangered,
Endangered or Vulnerable) on the IUCN Red List of
Threatened SpeciesTM. Most of the remaining species
are either Data Decient or Not Evaluated. The slow
growth and demersal nature of angel sharks leaves
them especially vulnerable to inshore shing activities.
Consequently, many species in this family have suered
steep population declines and now face a signicant risk
of extinction.
Once found throughout the temperate waters of the
Northeast Atlantic, Mediterranean and Black Seas, angel
sharks have now been depleted from much of their former
range. Of the three species that occur in these regions –
the Angelshark* Squatina squatina, Sawback Angelshark
Squatina aculeata and Smoothback Angelshark Squatina
oculata - most information is known regarding the
distribution, ecology and declines of Squatina squatina.
All three species are Critically Endangered.
About this Strategy
This Angel Shark Conservation Strategy provides a
framework for improved protection of the three Critically
Endangered species present in the Eastern Atlantic and
Mediterranean. The Strategy aims to: improve the overall
prole of angel sharks; increase the number of sightings
reported; generate a better understanding of current
distribution; contribute to IUCN Red List re-assessments
and identify new collaboration opportunities to increase
conservation action.
Some of the key threats to these species are outlined
within this Strategy. Three priority goals and associated
headline objectives have been identied as crucial to
achieving the vision that: Angel sharks in the Eastern
Atlantic and Mediterranean are restored to robust
populations and safeguarded throughout their range.
The recommended next steps outlined in this document
act as guidelines for targeted conservation actions.
Researchers and advocates in all regions are invited
to contribute additional information to support this
Strategy and help develop specic actions to safeguard
these Critically Endangered species.
*angel shark (as two words) refers to multiple species in the
family Squatinidae, while Angelshark (as one word) is used for
species common names.
Angelshark
Squatina squatina
Sawback Angelshark
Squatina aculeata
Smoothback Angelshark
Squatina oculata
Squatina squatina © Carlos Suarez, Oceanos de Fuego
1
Smoothback Angelshark Squatina oculata6
Former Range: Formerly common over large areas of coastal and outer continental shelf
areas in the Eastern Atlantic (from the southern Iberian peninsula down to Namibia) and
the Mediterranean Sea (more frequent in southern regions, e.g. Tunisia).
Current Range: Occasional reports are received from the West African coast as well as
the Eastern and Central Mediterranean.
Size: Reported to mature at 71 – 82 cm () and 89–100 cm ()
Maximum length 145 cm () and 160 cm ()
Remarks: As with S. squatina and S. aculeata, abundance has declined considerably during the
past 50 years due to intense demersal sheries operating throughout its range. Although this
species is likely still taken as incidental catch in trawl and gillnet sheries in some regions, it is
likely no longer present in large areas of the Mediterranean and parts of the West African coast.
Sawback Angelshark Squatina aculeata4
Former Range: Once widespread in the Eastern Atlantic (West African coasts from
Morocco to Angola) and Mediterranean Sea (Western and Central basins, Ionian Sea,
and Egyptian coasts).
Current Range: Only occasional reports of this species are now received, including
from the Eastern Mediterranean and parts of the West African coast.
Size: Estimated average length at maturity 124 cm
Maximum length ~188 cm
Remarks: It is dicult to conrm contemporary range as angel shark landings are reported
in aggregated categories5, masking species specic landings. Although likely still taken as
incidental catch, the total number of individuals caught is unquantied. Its habitat has been
subject to intense demersal sheries (including trawls, set nets and bottom longlines), as such,
this species is now rarely reported from large areas of its former range.
2
S. aculeata © Marc Dando
S. oculata © Marc Dando S. squatina © Marc Dando
Angelshark Squatina squatina2
Former Range: Historically common over large areas of the coastal, continental, and
insular shelf of the Northeast Atlantic (from southern Norway and the Shetland Islands
down to Morocco, West Sahara, and the Canary Islands), as well as the Mediterranean
and Black Seas.
Current Range: The Canary Islands provide a unique stronghold for this species,
oering the last known location where it can be regularly encountered. The
remainder of its range has drastically contracted and only occasional reports
are now received from the Eastern and Central Mediterranean, Adriatic Sea,
and Celtic Seas ecoregion. However, in recent years, there have been increased
reports from Cardigan Bay (Irish Sea).
Size: Reported to mature at 80 - 132 cm () and 128 - 169 cm ()
Maximum length 183 cm () and ~244 cm ()
Remarks: This is the only species of angel shark known in northern European seas. Range
has severely contracted during the past century, largely due to the intensication of
demersal shing practices. Urgent action is still required to further protect S. squatina in its
Canary Islands stronghold, to address this, a collaborative Angelshark Action Plan for
the Canary Islands3 was launched in late 2016.
S. squatina
S. aculeata
S. oculata
S. squatina & S. oculata
S. aculeata & S. oculata
Domestic protection
for S. squatina in
UK Waters (0-12 nm)I.
Regional protection for
S. squatina in EU Union Waters
with a Prohibition on retentionII.
Domestic protection for
Squatina spp. in Spanish
Mediterranean WatersIII.
Regular sightings of juvenile
(and adult) S. squatina7 in the
Canary IslandsIV.
Minimal knowledge of incidental or
targeted landings from the West
African coast.
Recent juvenile
record of S. oculata.
Despite prohibition in
Mediterranean, landings persist.
Recent juvenile
records of S. oculata9.
Territorial protection
for Squatina spp. in
Balearic Islands with
protective status in
Marine Protected Areas.
Recent juvenile
records of
S. aculeata8.
Recent known distribution since 1987
The retention of
24 species of elasmobranch
(including Squatina spp.)
are prohibited in the
Mediterraneanv.
In 2015, over 180 tonnes5 of
angel shark were reported as
landed from Mediterranean
Waters. Additional landings are
highly likely under aggregated
landings categories.
Legislative measures
Former range of Squatina spp.
Recent juvenile sightings
Landings information
Squatina spp.
Squatina spp. is used to refer to the three
species of angel shark found in these
regions, rather than the entire family.
Distribution and Management Measures
The distribution of these three angel shark species overlaps substantially and there is still a great deal of uncertainty
regarding contemporary range. Figure 1 reects the paucity of landings data and current management measures
in place (listed in Table 1). Recent reports of juveniles are also highlighted as they conrm the presence of breeding
stock and could help direct conservation action. The presence of these juveniles provides encouraging signs for
the future of these Critically Endangered species. Reports of adult and juvenile sightings can be viewed by visiting
the online sightings map at www.angelsharknetwork.com. This Strategy encourages the submission of data and
information by regional experts, contributing additional layers to the existing knowledge base.
Area Species Legislative/conservation measure
I UK S. squatina Wildlife and Countryside Act (1981); Northern Ireland Wildlife Order (1985); Scottish Elasmobranch
Protection Order (2012).
II EU Union Waters S. squatina Prohibited species under the EU Common Fisheries Policy Council Regulation (EC) 43/2009.
III Spanish
Mediterranean
Squatina
spp.
Domestic legislation in Spanish waters for Squatina spp. through the Spanish List of Species Under
Special Protection in the Mediterranean (LESPRE) Orden AAA/75/2012.
IV Canary Islands S. squatina Angelshark Action Plan for the Canary Islands.
V Mediterranean Squatina
spp.
Elasmobranch species on Barcelona Convention Annex II of the Protocol concerning Specially
Protected Areas and Biological Diversity in the Mediterranean (SPA/BD Protocol) for which GFCM
(GFCM/36/2012/3) Parties agreed to ban retention, landing, transhipment, storage, display, and sale.
Table 1. Details of map annotations for legislative and conservation measures
Figure 1. Current and former distribution of S.
squatina, S. aculeata, and S. oculata, key legislative
measures, and recent juvenile sightings.
3
Key Threats
Within this Conservation Strategy, the Eastern Atlantic and Mediterranean has been broken down into four sub-
regions: Northeast Atlantic, Canary Islands, West Africa, and the Mediterranean Sea. The potential threats faced
by angel shark populations are detailed in Table 2 using the headings outlined in the standardised IUCN Red List
threat classication criteria10. The most signicant direct threats are highlighted within the table and should be given
highest priority. Specialist input was sought through an online questionnaire and associated workshops, however
additional contributions would help identify specic regional threats and subsequent actions.
Table 2. Potential threats to angel sharks in the Eastern Atlantic and Mediterranean.
THREAT CATEGORIES
Agriculture &
Aquaculture
Biological
Resource Use
Climate
Change
& Severe
Weather
Human
Intrusion &
Disturbance
Invasive & Other
Problematic
Species, Genes
& Diseases
Natural System
Modication Pollution
Residential &
Commercial
Development
Transportation
& Service
Corridors
Aquaculture
cages
(hormones,
food etc.)
Illegal,
Unreported &
Unregulated
(IUU) shing
Changing
weather
temperature
Degradation of
habitat Pathogens
In-water
developments
aecting sediment
transport (e.g.
dykes)
Water
pollution/
runo
Coastal
building and
infrastructure
development
Pipelines &
electrical cables
Intensive
shellsh
management
Commercial
shing (lack
of species
specic
landings &
identication
issues)
Storms
destroying
habitat
Altered
seaoor
morphology
Low genetic
diversity (genetic
bottlenecks/
population
fragmentation)
Micro/macro
plastics
Renewable
energy (e.g.
wind farms,
underwater
turbines,
aggregate
extraction,
lagoons)
Shipping
disturbance
(e.g. physical
disturbance,
noise pollution)
Commercial
shing (impact
of diering
gear types)
Water runo
destroying
habitat
Anchor
damage of
habitats
Invasive species Desalination
plant pollution
Small scale/
artisanal shing
Severe
winters
Recreational
watersports
Predation on
juveniles Sewage
Subsistence/
food security Oil spills
Recreational
Fishing
Antibiotics/
hormones in
water course
Ghost shing Eutrophication
Alteration of
food chain
(overshing of
prey species)
Example threats for each geographic region:
Northeast Atlantic: commercial shing
The morphology of angel sharks twinned with their
demersal habitat makes them highly vulnerable to
targeted or incidental capture in a number of coastal
sheries. Despite some sheries restrictions, the actual
level of threat is masked by the lack of incidental catch
reporting or reporting under aggregated categories.
Canary Islands: recreational shing
Angel sharks are caught by recreational shers
throughout their range. In addition to the 50 registered
recreational charter vessels in the Canary Islands, there
are a substantial number of shore anglers, spearshers
and privately registered vessels catching S. squatina.
With no ocial catch reporting mechanisms, the
impact of this sector remains unquantied.
Mediterranean: poor implementation
Regulations or measures exist for the management
and protection of angel sharks in the Mediterranean,
however not all are implemented e.g. the General
Fisheries Commission for the Mediterranean
(GFCM/36/2012/3). The outward projection of
management infers that unregulated sheries no
longer pose a threat.
West Africa: small-scale shing
References to the consumption of angel shark are
fairly common throughout their range. Sharks are
an important source of protein to many coastal
communities, however the importance specically of
angel sharks to food security is unquantied. Market
surveys and data collection at a national level should
assist in ascertaining to what extent small-scale shing
poses a threat.
4
Vision, Goals and Objectives
Three priority goals are key to delivering the vision that: Angel sharks in the Eastern Atlantic and Mediterranean are
restored to robust populations and safeguarded throughout their range. The associated headline objectives identify
broad themes under which subsequent actions can be grouped (Table 3). Actions undertaken to help realise these
goals and objectives will be varied according to threat, geographic region and policy measures currently in place.
Table 3. Vision, goals and objectives of the Eastern Atlantic and Mediterranean Angel Shark Conservation Strategy.
Juvenile Squatina squatina © Michael Scholl
VISION
Angel sharks in the Eastern Atlantic and Mediterranean are restored to robust populations
and safeguarded throughout their range
GOAL 1
Fisheries based angel shark
mortality is minimised
GOAL 2
Critical Angel Shark Areas** are
identied, investigated and
protected where appropriate
GOAL 3
Human interactions are
identied and any negative
impacts on angel sharks
are minimised
OBJECTIVE 1 Reporting and monitoring
in commercial sheries is
improved
Distribution and presence
of angel shark is conrmed
and areas of importance are
identied and mapped
The extent of human
interaction in each region is
understood
OBJECTIVE 2 Existing legislative measures
to protect angel sharks
are implemented through
enforcement and monitoring
Human impact in Critical Angel
Shark Areas is quantied and
evaluated
The impact of renewable
and extractive industries on
angel shark populations is
understood
OBJECTIVE 3 Gaps in protective measures
are identied and appropriate
legislation to ll these gaps is
developed and implemented
Critical Angel Shark Areas
are protected through spatial
management
Critical Angel Shark
Areas are considered
prior to nearby coastal
development so impacts
are mitigated
OBJECTIVE 4 Improved sher knowledge
of angel sharks’ threat status
reduces retention and
encourages better handling to
improve post release survival
Angel sharks are protected
by regional and domestic
management measures
The extent of angel shark
related tourism in each
region is assessed and
any interactions with angel
sharks is understood
OBJECTIVE 5 Incidental catch of angel sharks
is quantied and minimised
OBJECTIVE 6 The extent of interaction
between recreational shing
activities and angel sharks is
ascertained
**A Critical Angel Shark Area is dened as:
A specic geographic area that contains essential features necessary
for the conservation of angel sharks. This may include an area that is not
currently occupied by the species that will be needed for its recovery
or conservation e.g. nursery, mating, aggregation and foraging areas.
5
Threat Priorities
Priorities to address some of the recognised threats and headline objectives have been outlined, however
additional priorities will be identied through further engagement with regional experts. Overarching threats and
recommended actions include, but are not limited to:
Commercial sheries: assess landings data; identify incidents of non-compliance; identify lack of management
implementation; advocate for implementation in appropriate fora.
Incidental catch: engage with regional sheries bodies; improve incidental catch reporting; identify sheries
with signicant incidental catch; provide guidance on best practice to increase post-release survival; initiate
incidental catch mitigation measures.
Recreational angling: compile regional registers of recreational charter vessels and associated outlets; provide
identication materials; encourage sightings and catch reporting.
Critical Angel Shark Areas: engage with local shermen and researchers to inform distribution; provide species
identication materials; identify potential critical habitats; investigate migratory behaviour; map ndings.
Human interactions: identify key activities (e.g. diving, tourism, coastal development); map likely hot-spots of
human interaction (both positive and negative); undertake surveys to quantify the level and nature of interactions.
Geographic Priorities
More specic priorities for each geographic region include:
Policy Priorities
Eective legislative protection twinned with a reduction in incidental catch mortality are key to delivering
the vision of this Conservation Strategy. Key policy objectives have been identied, and additional domestic
regulation opportunities sought.
Priorities - H: High M: Medium
Costs - $: Low cost (likely with existing budget) $$: Medium cost (additional funding may be required)
Key Policy Actions Priority Cost
Listing on Spanish Domestic Regulations (based on priorities within the Angelshark Action
Plan for the Canary Islands).
H $
Implementation of General Fisheries Commission for the Mediterranean (GFCM) measures. H $
Expansion of Common Fisheries Policy (CFP) to include additional Squatina spp.H $
Listing on Convention of Migratory Species (CMS) (if data available on migratory behaviour). M $$
Other national management measures as identied. M $$
Table 4. Key policy actions with associated priorities and costs.
Northeast Atlantic
Whilst S. squatina benets from Prohibited status in
much of the Northeast Atlantic, the next steps should
include:
secure management for additional Squatina spp.
under the EU Common Fisheries Policy;
quantify incidental catch in commercial and
recreational sheries.
Canary Islands
The Angelshark Action Plan for the Canary Islands
provides a clear framework for the delivery of specic
goals, objectives and actions in this unique stronghold
for S. squatina. This Action Plan could be considered
as a model for regional engagement.
Download the Action Plan in English or Spanish from:
www.angelsharknetwork.com.
Mediterranean
Recent publications have reported the presence of
adult and juvenile angel sharks (both S. aculeata7 and
S. oculata8) in the Mediterranean, potentially indicating
the presence of breeding stock. Next steps include:
enhance understanding of species distribution;
quantify incidental catch;
enforce existing management measures.
West Africa
West Africa is a priority region which perhaps poses
some of the greatest challenges, with little published
information currently available. Next steps include:
further engage with regional experts;
quantify landings and distribution;
understand secondary uses;
identify management opportunities.
6
How to engage with this Strategy
Further details and supporting materials to this summary document can be found at www.angelsharknetwork.com.
Here you can:
Submit angel shark sightings
Join the Angel Shark Conservation Network (ASCN)
Download additional resources
Access the latest angel shark news and research
Angel shark questionnaire: if you have supplementary information about angel sharks in the Eastern Atlantic and
Mediterranean, please visit www.bit.ly/2qeVzDJ and complete the questionnaire. Additional information provided
will help enhance this Conservation Strategy and allow expansion of the angel shark community.
If you would like further information on this document, please contact angels@sharktrust.org.
CITATION: Gordon, C.A., Hood, A.R., Barker, J., Bartolí, À.,
Dulvy, N.K., Jiménez Alvarado, D., Lawson, J.M., and Meyers,
E.K.M. (2017) Eastern Atlantic and Mediterranean Angel Shark
Conservation Strategy. The Shark Trust.
WORKSHOP PARTICIPANTS (L-R): Riley Pollum, Jo Barker,
David Jiménez Alvarado, Eva Meyers, Jim Ellis, Rowland
Sharp, Sonja Fordham, Heike Zidowitz, Cat Gordon, Sarah
Fowler, Ali Hood, Julia Lawson, Àlex Bartolí. Not pictured:
Martin Clark, Nick Dulvy, Colin Simpfendorfer.
FUNDERS:
REFERENCES
1. Dulvy, N.K. et al. (2014) Extinction risk and conservation of the world’s sharks and rays. eLife 3: e00590.
2. Ferretti, F. et al. (2015) Squatina squatina. IUCN Red List of Threatened Species: e.T39332A48933059.
3. Barker, J. et al. (2016) Angelshark Action Plan for the Canary Islands.
4. Morey, G. et al. (2007) Squatina aculeata. IUCN Red List of Threatened Species: e.T61417A12477164.
5. FAO FishStat Plus - Universal software for shery statistical time series. Rome. www.fao.org/shery/statistics/software/shstat/en (landings updated to 2015).
6. Morey, G. et al. (2007) Squatina oculata. IUCN Red List of Threatened Species: e.T61418A12477553.
7. Meyers E.K.M. et al. (2017) Population structure, distribution and habitat use of the Critically Endangered Angelshark, Squatina squatina, in the Canary
Islands. Aquatic Conserv: Mar Freshw Ecosyst.
8. Başusta, N. (2016) New records of neonate and juvenile sharks (Heptranchias perlo, Squatina aculeata, Etmopterus spinax) from the North-eastern
Mediterranean Sea. Mar Biodiv 46: 525-527.
9. Zava, B. et al. (2016) Occurrence of juvenile Squatina oculata Bonaparte, 1840 (Elasmobranchii: Squatinidae) in the Strait of Sicily (Central Mediterranean).
Cybium 40 (4): 341-343.
10. Salafsky et al. (2008) A standard lexicon for biodiversity conservation: unied classications of threats and actions. Conserv. Biol. (4): 897 - 911.
Juvenile Squatina squatina © Tom Young
7
Summary
This Conservation Strategy provides a summary of available information for the three species of angel shark in the
Eastern Atlantic and Mediterranean. Threats, goals and objectives are outlined, however this document acts as an
invitation for interested individuals to contribute relevant research for the highlighted regions. It is the intention that
this Strategy serves as a catalyst for action, bringing together regional experts and resources, and increasing the
community’s capacity to deliver eective conservation for these Critically Endangered species.
From clarity of species distribution, understanding of cultural signicance, quantication of incidental catch rates, to
eective implementation of both existing and new management criteria and beyond – there is a great deal of work
to do and opportunity for interested parties to get involved.
The Eastern Atlantic and Mediterranean Angel Shark
Conservation Strategy aims to:
improve the overall prole of angel sharks;
increase the number of sightings reported;
generate a better understanding of current distribution;
contribute to IUCN Red List re-assessments;
identify new opportunities for collaboration.
This Conservation Strategy was created following workshops held
in Las Palmas (Gran Canaria) and Bristol (UK) in 2016 and having
reviewed questionnaire responses submitted by additional experts.
Squatina squatina © Michael Sealey
8
June 2017
... The Mediterranean Sea is an important habitat for cartilaginous fish (Bradai, Saidi, & Enajjar, 2018), and hosts three angel shark species; the sawback angelshark (Squatina aculeata Cuvier, 1829), the smoothback angelshark (Squatina oculata Bonaparte, 1840) Gordon et al., 2017;Miller, 2016;Nieto et al., 2015;Walker, Cavanagh, Ducrocq, & Fowler, 2005). Currently, their distribution in the basin appears scattered with several local extinctions (Ferretti et al., 2016;Gordon et al., 2017;Soldo & Bariche, 2016); however, observations are extremely limited and the species are commercially extinct (Cavanagh & Gibson, 2007;Gordon et al., 2017;Zoological Society of London, 2018). ...
... The Mediterranean Sea is an important habitat for cartilaginous fish (Bradai, Saidi, & Enajjar, 2018), and hosts three angel shark species; the sawback angelshark (Squatina aculeata Cuvier, 1829), the smoothback angelshark (Squatina oculata Bonaparte, 1840) Gordon et al., 2017;Miller, 2016;Nieto et al., 2015;Walker, Cavanagh, Ducrocq, & Fowler, 2005). Currently, their distribution in the basin appears scattered with several local extinctions (Ferretti et al., 2016;Gordon et al., 2017;Soldo & Bariche, 2016); however, observations are extremely limited and the species are commercially extinct (Cavanagh & Gibson, 2007;Gordon et al., 2017;Zoological Society of London, 2018). ...
... The Mediterranean Sea is an important habitat for cartilaginous fish (Bradai, Saidi, & Enajjar, 2018), and hosts three angel shark species; the sawback angelshark (Squatina aculeata Cuvier, 1829), the smoothback angelshark (Squatina oculata Bonaparte, 1840) Gordon et al., 2017;Miller, 2016;Nieto et al., 2015;Walker, Cavanagh, Ducrocq, & Fowler, 2005). Currently, their distribution in the basin appears scattered with several local extinctions (Ferretti et al., 2016;Gordon et al., 2017;Soldo & Bariche, 2016); however, observations are extremely limited and the species are commercially extinct (Cavanagh & Gibson, 2007;Gordon et al., 2017;Zoological Society of London, 2018). ...
Article
1. All three species of angel sharks (genus Squatina) inhabiting the Mediterranean Sea are listed as Critically Endangered in the International Union for Conservation of Nature Red List of Threatened Species due to overexploitation. 2. New records from Cyprus, Greece, Italy and Libya were collected from citizenscientists and integrated with local knowledge obtained using structured interviews in the four countries. 3. Observations and reports, together with an analysis of the reconstructed fisheries data, resulted in the identification of areas of interest, a review of the illegal trade of the species and a debate about the credibility of fisheries data for assessing threatened and/or protected species. 4. Unconventional sources of information, such as social media, were identified as important tools for monitoring rare and endangered marine wildlife. 5. This work will contribute to promoting international cooperation for advancing angel shark conservation in line with the Eastern Atlantic and Mediterranean Angel Shark Conservation Strategy.
... The West Africa region is home to a specialised elasmobranch industry of fisheries, processing and trade, which was started in The Gambia by Ghanaian immigrants (Walker et al. 2005;Diop and Dossa 2011). Furthermore, West Africa also has been identified as one of five global hotspots to prioritize for conservation of chondrichthyans based on species richness, endemism and evolutionary distinctness, and as a priority region for the conservation of Critically Endangered angel sharks (Gordon et al. 2017;Stein et al. 2018). Despite this importance, little is known about elasmobranch biodiversity and fisheries in West Africa, although there has been some work focusing on reproductive biology of a few species (Capapé et al. 2002;Seck et al. 2004;Valadou et al. 2006). ...
... In April 2017 a smoothback angel shark Squatina oculata of an estimated 100 cm TL was found split and dried with pectoral, dorsal and caudal fins removed (Table 1, Fig. 6a); in March 2018, a single whole female of the sawback angelshark Squatina aculeata of an estimated 150 cm TL was recorded, which also had dorsal and caudal fins removed (Table 1, Fig. 6b). All three species of Squatina from the eastern Atlantic are Critically Endangered based on former abundance, severe fishery-driven declines and rarity of recent records, and quantifying landings in West Africa is a conservation priority given minimal current knowledge (Morey et al. 2007a, b;Gordon et al. 2017). Diop and Dossa (2011) recorded S. oculata and S. aculeata as 'frequent' and 'quite frequent' respectively in mainland SFRC countries, but this is in marked contrast to the narrative from other data sources (e.g. from Russian trawl surveys and Senegalese artisanal fishers) which reported both species as being common around the 1970 s and 1980 s, but as extremely rare now. ...
... Regional research surveys recorded very sparse occurrence, with the last Gambian records for S. oculata consisting of six individuals between 1986 to 2000, and of a single S. aculeata in 1998 (Morey et al. 2007a, b). The removal of fins recorded in our surveys is of interest given that the shark fin trade has not previously been identified as a specific threat to Squatina species Morey et al. 2007a, b;Gordon et al. 2017). ...
Article
Full-text available
Developing nations in tropical regions harbour rich biological resources on which humans depend for food, income and employment, yet data to aid their management is often lacking. In West Africa, the diversity and fisheries of elasmobranchs are poorly documented, despite them being known to be economically important and vulnerable to overexploitation. Rapid qualitative surveys of fish processing and landing sites in The Gambia from 2010-2018 revealed valuable new data on species composition, biology, relative abundance, fisheries and utilisation by humans. Diversity and abundance was dominated by batoids, with a major component comprising a large guitarfish (Glaucostegus cemiculus) that was apparently targeted, and a small whipray (Fontitrygon margaritella). Nearly all taxa recorded are classified by the IUCN Red List as Critically Endangered (angel sharks Squatina spp.), Endangered, Data Deficient, or Not Evaluated; several were endemic, of exceptional evolutionary distinctness, cryptic, possibly undescribed, and rare (including stingray Hypanus rudis not apparently recorded since description in 1870). Significant threats to biodiversity, coastal livelihoods and possibly food security are identified based on the apparent importance of elasmobranch fisheries and processing; the known inability of key taxa to withstand intensive fisheries; ‘fishing down the food web’ by intensive utilisation of F. margaritella; and the absence or rarity of previously common elasmobranch species that may be severely depleted in the region. This study provides data that may act as a starting point to aid sustainability accreditation of local fin-fisheries, and demonstrates the value of inexpensive and low-resolution data collection in developing countries.
... Squatina oculata is classified as "Critically Endangered" in the Global Red List by the International Union for Conservation of Nature (IUCN, 2018). Gordon et al. (2017) stated that the Angel Shark Conservation Strategy aims to conserve the three Critically Endangered angelshark species (S. aculeata, S. oculata and S. squatina) found in the Eastern Atlantic and Mediterranean. Thus, they determined key components to improve the overall profile of angelsharks: (i) increase the number of sightings reported, (ii) generate a better understanding of current distribution to contribute to IUCN Red List re-assessments and (iii) identify new opportunities for collaboration. ...
Article
Full-text available
Abstract: One female specimen of the Smoothback Angelshark Squatina oculata was captured by a commercial trawler at a depth of 65 m on 4 November 2017 from Aydıncık coast (North-eastern Mediterranean Sea, Turkey). Squatina oculata had not been reported in this part of the North-eastern Mediterranean Sea nearly for the last two decades. The captured specimen was 726 mm in total length and 3450 g in weight. Morphometric and meristic characters of the captured specimen are compared with the other Mediterranean records. Due to increasing fishing activities and habitat degradation throughout the Mediterranean Sea during the last decades, angelshark species are dramatically declined day by day. Thus, conservation status of the Smoothback Angelshark S. oculata in the Mediterranean Sea is classified as “Critically Endangered” at Global Red List by IUCN.
Article
Angel sharks (Squatina spp.) are distributed in warm temperate to tropical waters around the world. Many species occur in shelf seas and exhibit seasonal inshore‐offshore migrations, moving inshore to give birth. Consequently, there can be high spatial overlap between angel shark populations with fisheries and other human activities. Their dorso‐ventrally flattened body shape, large size (most species attain >100 cm total length, LT) and demersal nature means that they may be taken in a variety of demersal fishing gears from birth. Available data indicate that angel sharks typically have a biennial reproductive cycle, with litter sizes generally <20 and the young born at ca. 20–30 cm. The biological characteristics of angel sharks render them susceptible to overexploitation, as exemplified by the decline of Squatina squatina from many parts of its former range in the North‐east Atlantic and Mediterranean Sea. Currently, half of the 22 recognised extant species of angel shark are classed as Threatened on the International Union for Conservation of Nature (IUCN) Red List (with a further three classified as Data Deficient). Given the biological vulnerability of angel sharks, and that many species are data‐limited, the current paper provides a review of available biological information and fisheries data pertaining to this family. This article is protected by copyright. All rights reserved.
Article
Full-text available
Marine extinctions are particularly difficult to detect and almost all have been discovered after the fact. Retrospective analyses are essential to avoid concluding no‐extinction when one has occurred. We reconstruct the Angelshark population trajectory in a former hotspot (Wales), using interviews and opportunistic records. After correcting for observation effort and recall bias, we estimate a 70% (1.5%/year) decline in abundance over 46 years. While formerly widespread, Angelshark distribution contracted to a central core of Cardigan Bay. Angelshark declined almost unnoticed in one of the best‐monitored and most intensively managed seas in the world. Bycatch may be minimized by limiting netting on shingle reefs in Cardigan Bay. We provide the first quantitative time series to reveal the timing and trajectory of decline of Angelshark in the coastal waters of Wales and uncover historical centers of abundance and remnant populations that provide the first opportunity for the focus of conservation.
Article
Full-text available
Two out of three critically endangered species of angelsharks (genus Squatina (Dumeril, 1806)) inhabiting the Mediterranean have been recorded in the Adriatic Sea, namely smoothback angelshark S. oculata Bonaparte, 1840 and common angelshark S. squatina (Linnaeus, 1758). While S. oculata has been extirpated from the Adriatic Sea due to overfishing, the presence of S. squatina remained questionable and some authors propose the species is regionally extinct since the 1980s. We present new data on the occurrence of S. squatina in the Croatian Adriatic Sea based upon inspection of collections from natural history museums and literature sources as well as three new records resulting from bycatch in commercial bottom trawls in 2016 and 2017. A low overall number of records and the complete absence of the species in scientific trawl surveys conducted since 1958, indicate its low abundance and question the effectiveness of scientific surveying in detecting rare species. Our analysis showed that this formerly abundant species is still present in the Adriatic Sea, emphasizing the importance of implementing novel approaches, such as citizen-science programmes, in studying its current distribution. Although the legal framework for angelshark conservation already exists, poor implementation and lack of any species-specific conservation measures will most probably result in further population declines and extinction of S. squatina from the Adriatic Sea.
Article
Full-text available
1. Angel sharks are among the most threatened fish worldwide, facing regional and global extinction. In Europe, populations of the three Critically Endangered angel sharks (Squatina aculeata, Squatina oculata and Squatina squatina) have been severely depleted. 2. Taking advantage of the last global 'hotspot' of the angelshark, Squatina squatina, this study gathered data through a citizen science programme to describe the occurrence of this shark in the coastal waters of the Canary Islands. Specifically, this study described (1) the population structure, and (2) habitat use of this species, which was used in a Species Distribution Model to (3) examine realized and potential distribution patterns, and to (4) determine the relative importance of environmental predictors on the occurrence of S. squatina. 3. Over the 12 months sampling period (April 2014 – March 2015), 678 sightings were reported. Individuals ranged from 20 to 200 cm (total length). Larger sightings of both females and neo-nates occurred mostly in April to July, i.e. during the pupping season. Males were significantly more frequent in November to January, i.e. during the mating season. Angelsharks were encountered at depths from <1 m to a maximum of 45 m. Small‐sized individuals (i.e. neonates) exclusively occurred in shallow water (0–25 m). Most sharks occurred on sandy bottoms adjacent to reefs. 4. Even though sightings were recorded at all seven islands in the archipelago, there were fewer encounters in the western than the eastern islands. 5. The Species Distribution Model indicated that the probability of occurrence mainly correlated with sea surface temperature, chlorophyll, salinity and depth. Areas with the greatest habitat suitability were in shallow water. 6. The angelshark displayed spatial (vertical and horizontal) and temporal segregation by size and sex. This information is vital to inform conservation of this Critically Endangered shark in its last stronghold.
Article
Full-text available
Résumé. – Présence de juvéniles de Squatina oculata Bonaparte, 1840 (Élasmobranches: Squatinidae) dans le détroit de Sicile (Méditerranée centrale). Quatre juvéniles de Squatina oculata, de longueur totale com- prise entre 291 et 564 mm, ont été capturés en septembre 2007 par un chalut de fond dans les eaux côtières du détroit de Sicile. En raison de la rareté de cette espèce, les principales caractéristiques biométriques sont rapportées. Compte tenu de leur taille, et dans un cas très proche de la taille à la naissance, les spécimens collectés ont été enregistrés comme des juvéniles. Cette présence de juvéni- les suggère que cette espèce “en danger critique” est encore capable de se reproduire au large de la côte sud de la Sicile.
Technical Report
Full-text available
The Angel Shark Project (a joint project created by the Universidad de Las Palmas de Gran Canaria, Zoological Society of London, and Zoologisches Forschungsmuseum Alexander Koenig), the IUCN Shark Specialist Group and the Shark Trust organised a four-day workshop in Gran Canaria in June 2016 to develop the Angelshark Action Plan for the Canary Islands. The workshop brought together a multi- disciplinary group of stakeholders (divers, scientists, conservation organisations, local and international shark experts alongside the Canary Island Government and Spanish Government), to identify and address the major threats to Angelshark populations. The Angelshark Action Plan is a living document; organisations or individuals are welcome to help or lead the implementation of each action and to add new priorities to the plan if identified (See Angel Shark Conservation Network (ASCN) page 27 ). All interested parties are invited to help achieve the actions set out in the Angelshark Action Plan, working with a joint vision that Angelsharks in the Canary Islands are abundant and protected in their unique stronghold. The Angelshark Action Plan is a key component of the wider Eastern Atlantic and Mediterranean Angel Shark Conservation Strategy, developed to conserve the three Critically Endangered angel shark species found in the region: Angelshark (Squatina squatina), Smoothback Angelshark (Squatina oculata) and Sawback Angelshark (Squatina aculeata). This document will eventually play an important role in a Global Conservation Strategy for all species of angel shark.
Article
Three species of neonate and juvenile sharks (Heptranchias perlo, Squatina aculeata, Etmopterus spinax) were captured as by-catch from a commercial trawl fishing from depths between 360 and 430 m in the Northeastern Mediterranean Sea. Two neonates of H. perlo, five neonates of E. spinax and one juvenile of S. aculeata were for the first time identified in the above region.
Article
An essential foundation of any science is a standard lexicon. Any given conservation project can be described in terms of the biodiversity targets, direct threats, contributing factors at the project site, and the conservation actions that the project team is employing to change the situation. These common elements can be linked in a causal chain, which represents a theory of change about how the conservation actions are intended to bring about desired project outcomes. If project teams want to describe and share their work and learn from one another, they need a standard and precise lexicon to specifically describe each node along this chain. To date, there have been several independent efforts to develop standard classifications for the direct threats that affect biodiversity and the conservation actions required to counteract these threats. Recognizing that it is far more effective to have only one accepted global scheme, we merged these separate efforts into unified classifications of threats and actions, which we present here. Each classification is a hierarchical listing of terms and associated definitions. The classifications are comprehensive and exclusive at the upper levels of the hierarchy, expandable at the lower levels, and simple, consistent, and scalable at all levels. We tested these classifications by applying them post hoc to 1191 threatened bird species and 737 conservation projects. Almost all threats and actions could be assigned to the new classification systems, save for some cases lacking detailed information. Furthermore, the new classification systems provided an improved way of analyzing and comparing information across projects when compared with earlier systems. We believe that widespread adoption of these classifications will help practitioners more systematically identify threats and appropriate actions, managers to more efficiently set priorities and allocate resources, and most important, facilitate cross-project learning and the development of a systematic science of conservation. Resumen: Un fundamento esencial de cualquier ciencia es un lexicón estándar. Cualquier proyecto de conservación puede ser descrito en términos de los objetivos de biodiversidad, directas amenazas, factores subyacentes en el sitio del proyecto y las acciones de conservación que el equipo está empleando para cambiar la situación. Estos elementos comunes se pueden eslabonar en una cadena causal, que representa una teoría de cambio de cómo las acciones de conservación alcanzarán los resultados deseados. Si los equipos de los proyectos quieren describir y compartir su trabajo y aprender uno de otro, se requiere un lexicón estándar y preciso para describir específicamente cada nodo a lo largo de esta cadena. A la fecha, ha habido varios esfuerzos independientes para desarrollar clasificaciones estándar para las amenazas directas que afectan la biodiversidad y las acciones de conservación requeridas para contrarrestar estas amenazas. Reconociendo que es mucho más efectivo tener solo un esquema global aceptado, combinamos estos esfuerzos separados en clasificaciones unificadas de amenazas y acciones, que presentamos aquí. Cada clasificación es un listado jerárquico de términos y definiciones asociadas. Las clasificaciones son integrales y exclusivas de los niveles superiores de la jerarquía, expandibles en los niveles inferiores y simples, consistentes y escalables en todos los niveles. Probamos estas clasificaciones aplicándolas post hoc a 1191 especies amenazadas de aves y 737 proyectos de conservación. Casi todas las amenazas y acciones podrían ser asignadas a los nuevos sistemas de clasificación, salvo algunos casos que carecen de información detallada. Más aun, los nuevos sistemas de clasificación proporcionaron una mejor manera de analizar y comparar información en proyectos cuando son comparados con sistemas previos. Consideramos que la adopción generalizada de estas clasificaciones ayudará que practicantes identifiquen amenazas y acciones apropiadas más sistemáticamente, manejadores definan prioridades y asignen recursos más eficientemente y, más importante, facilitar el aprendizaje y el desarrollo de una ciencia de la conservación sistemática.