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Seagrass habitats are under serious threat from diverse natural and human pressures, and calls for restoration measures to revive these invaluable habitats along the coast of India. This study compares three types of seagrass sprig restoration methods, namely PVC frames, bamboo frames and coir nets, to identify the best eco-friendly and cost-effective method suitable for community-based seagrass restoration projects. This study found that recovery of PVC frame for reuse partly damaged rhizomes. The cost for labour and materials for bamboo and coir method is lesser than the PVC frames. Coir ropes are flexible, light weight, easily available and the nets can be fabricated locally unlike PVC frames, the tubes for which have to be sourced from elsewhere. Coir nets can be tied with large number of seagrass sprigs fast, needs no technical manpower, and can be done involving local communities. This study observed more macrofaunal settlements in coir plots than bamboo and PVC frames. The material cost of bamboo frame was 46% lesser than the PVC frame, and same cost of coir frame was 102% lesser than the PVC frame. The labour cost of bamboo frame was 47% lesser than the PVC frame, and the same cost of coir frame was 33% lesser than the PVC frame. Thus, naturally degradable bamboo and coir nets are better, whereas coconut coir net method is the best as it is relatively of low cost, easily available and suitable for large scale, community-based seagrass restoration.
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J. Mar. Biol. Ass. India, 62 (1), January-June 2020
Available online at: www.mbai.org.in doi:10.6024/jmbai.2020.62.1.2137-13
Abstract
Seagrass habitats are under serious threat from diverse natural and
human pressures, and calls for restoration measures to revive these
invaluable habitats along the coast of India. This study compares
three types of seagrass sprig restoration methods, namely PVC
frames, bamboo frames and coir nets, to identify the best eco-
friendly and cost-effective method suitable for community-based
seagrass restoration projects. This study found that recovery of PVC
frame for reuse partly damaged rhizomes. The cost for labour and
materials for bamboo and coir method is lesser than the PVC frames.
Coir ropes are flexible, light weight, easily available and the nets can
be fabricated locally unlike PVC frames, the tubes for which have to
be sourced from elsewhere. Coir nets can be tied with large number
of seagrass sprigs fast, needs no technical manpower, and can be
done involving local communities. This study observed more
macrofaunal settlements in coir plots than bamboo and PVC frames.
The material cost of bamboo frame was 46% lesser than the PVC
frame, and same cost of coir frame was 102% lesser than the PVC
frame. The labour cost of bamboo frame was 47% lesser than the
PVC frame, and the same cost of coir frame was 33% lesser than the
PVC frame. Thus, naturally degradable bamboo and coir nets are
better, whereas coconut coir net method is the best as it is relatively
of low cost, easily available and suitable for large scale, community-
based seagrass restoration.
Keywords: Seagrass restoration, Palk Bay, dugongs, community-based
conservation, Cymodocea serrulata, Syringodium isoetifolium
Introduction
Marine coastal habitats like seagrass beds are key ecosystems
for humanity, providing valuable socio-economic and ecological
services (Bayraktarov
et al.
, 2015). The ecosystem services
of mangroves, coral reefs and seagrass beds have intricate
linkages, especially by the presence of similar fauna as adults
and juveniles (Bosire
et al.
, 2012). However, marine coastal
habitats are degrading due to a variety of human activities (Lotze
et al.
, 2006). These eventually cause distress to the social and
economic status of coastal communities, in local level and gross
income at national level in developing countries that once had
immensely benefitted from the marine coastal habitats. Hence,
it is important to conserve and manage the coastal marine
habitats like seagrass beds, and restore the degraded habitats
to sustain benefits to the dependent communities. Further, since
seagrass ecosystems are globally recognized as sinks for blue
carbon helping in sequestering atmospheric carbon (Kennedy
et al.
, 2010), seagrass restoration will help in ameliorating
the climate change. Fourteen species of seagrasses have been
Comparison of seagrass restoration
methods adopted in Palk Bay, India
V. Balaji*, V. Sekar and G. Murugesan
OMCAR Palk Bay Centre, Velivayal - 614 701, Thanjavur District, Tamil Nadu, India.
*Correspondence e-mail:
director@omcar.org
Received: 15 Dec 2019 Accepted: 25 July 2020 Published: 30 July 2020 Original Article
Journal of the Marine Biological Association of India Vol. 62, No.1, January-June 2020
V. Balaji
et al.
96
recorded in India and they are distributed in Andaman and
Nicobar Islands, Lakshadweep Islands, east and west coast of
mainland (Thangaradjou
et al.
, 2009). Seagrass beds in Palk
Bay and Gulf of Mannar are degraded due to various manmade
and natural threats (Thangaradjou
et al.
, 2009)
It is essential that degraded coastal ecosystems be brought back
to previous stage by restoration and it is possible (Nobi
et al.
,
2013) by adopting appropriate techniques. Restoration projects in
general aim bringing back the degraded ecosystem and associated
flora and fauna close to its original condition, and provide the
benefits to dependent communities (Wiens and Hobbs, 2015)
in a sustainable manner. Looking at the fast rate of degradation
and diverse anthropogenic pressures, there is dire need to focus
on appropriate techniques and tools for restoring the degraded
coastal ecosystems (Zhang
et al.
, 2018). Diverse seagrass restoration
methods are followed in different parts of the world (Bologna and
Sinnema, 2012; Marion and Orth, 2010; Bell
et al.
, 2008; Eriander
et al.
, 2016). In the case of seagrass restoration in developing
countries, it is appropriate that the techniques are community
based, low cost, eco-friendly and replicable. Thus, this study was
carried out in 2017 in parallel with the seagrass rehabilitation
project funded by Tamil Nadu Forest Department, Government of
Tamilnadu, under their dugong conservation action plan in Palk
Bay. Seagrass beds in Palk Bay, southeast coast of India, have
undergone much degradation mainly due to activities associated
with fishing and algal growth (Mathews
et al.
, 2010), a common
issue in coastal states. The aim of the study is to identify the most
efficient, low cost, eco-friendly seagrass transplantation frames
(PVC vs. Bamboo vs. Coir net) using sprig method, replicable for
community-based seagrass restoration projects around the world.
Material and methods
The transplantation site is located at Manora (Lat 10°14'52.34"
N, Long 79°18'34.14"E), a coastal village in northern Palk Bay
(Fig. 1). It is located about 1.3 km from the shoreline and 1.5
km from a natural seagrass bed that served as the donor site
in the present study. The site is selected based on the seagrass
acoustic survey conducted earlier (Balaji, 2018) and after detailed
interactions with the local fishers. Here, macroalgal beds were
also seen spread often up to 1 km from the shoreline.
Of the several methods tested, sprig method using square
shaped PVC frames has been considered as the most feasible
seagrass transplantation in Gulf of Mannar (Edward
et al.
,
2019). In the present study, the seagrass sprigs, collected from
natural seagrass meadows by scuba diving, were transported
to a boat, and tied on to PVC and bamboo frames and coconut
coir net with participation of local fishers. Each transplantation
frame was laid in an area of 100 m2 at a depth of ~4 meters.
Two common seagrass species namely
Cymodocea serrulata
and
Syringodium isoetifolium
were collected from the donor
site, which is about 1 km from the transplantation site. In the
transplantation site, PVC frames, Bamboo frames and coir nets
(made of coconut fibre) were installed at 4m depth. The details
of the three methods were compared as follows.
PVC frame method
This method was followed as per the Seagrass Rehabilitation
Project Guidelines developed under Dugong Conservation
Action Plan of Tamil Nadu Forest Department. Four PVC pipes
(2 cm diameter and 1 meter long) joined using “L” bend to
make 1m2 frames were filled with sand to add weight to settle
on the sea floor. After sealing the tubes using water-resistant
adhesives, jute ropes were tied inside these frames to form
square webs. The seagrass sprigs collected from donor sites
were attached to these jute ropes (120 sprigs per frame), and
the frame along with sprigs were submerged and fixed on the
seabed using “U” shaped iron clamps. In total 100 such PVC
frames (100 m2) were installed on the seabed.
Bamboo frame method
Frames (1 m2 size) were made using 2 cm wide and 1 m long
bamboo slivers (Fig. 2). Jute ropes were tied in the bamboo
Fig. 1. Map of Palk Bay showing study area in northern Palk Bay
© Marine Biological Association of India
Comparison of seagrass restoration methods adopted in Palk Bay
97
parameters (Atmospheric temperature, water temperature, salinity
and pH) were recorded every month. As the experimental sites are
located close to each other, water samples for nutrients such as
phosphate, nitrate and nitrite were collected from the mid-point
of the three plots and analysed following Strickland and Parsons
(1972) every month. Pearson correlations were computed among
environmental parameters, seagrass growth and macro fauna
density for the three samplings in 3rd, 5th and 7th month of the
experiment. The seagrass growth between the three sites was
compared using Chi- square test in SPSS software.
Results and discussion
The study observed maximum atmospheric temperature (35.2°C)
in May and minimum temperature in September (28°C) in
the sites selected (Fig. 4). The maximum water temperature
was recorded as 34.1 °C in May and minimum as 26°C in
September. Similar patterns were observed in salinity, and pH
level showed minor variations. All the three nutrients such as
nitrate, nitrite and phosphate were observed to be the maximum
in May and minimum in September (Fig. 5). Mean percentage
cover (Fig. 6), shoot density (Fig. 7) and macro fauna density
(Table 1) gradually increased with time in all the three types of
frames and no significant difference was observed between the
three, showing that seagrass growth pattern is similar among
the selected methods. The macrofauna such as gastropods
(1.6±0.04), bivalves (2.2±0.05), echinoderms (2±0.05),
coelenterates (2.6±0.05) and crustaceans (1.9±0.05) were
observed in higher numbers in coir plots, where more sponges
were observed in bamboo plots. No shoots and leaves were
observed after one month of transplantation, but the live
rhizomes with new roots were found extending into the sediment.
The new shoots came up after ~40 days of transplantation
in both
Cymodocea serrulata
and
Syringodium isoetifolium
.
Similar trend was observed in seagrass growth in all the three
plots possibly due to two reasons; a) Similarity between the
plots in terms of water quality, depth and distance from the
shoreline, and b) The experiment was started in the beginning
of summer and completed at the end of summer, when there
frame and 120 seagrass sprigs were tied on to it in the same
pattern as the PVC frames. Then the frames were fixed on
the seafloor using “U” shaped iron clamps. In total 100 such
bamboo frames (100 m2) were installed.
Coir frame method
Coir ropes were tied to make nets of 3-meter width and 6-meter
length (18 m2) with mesh size similar to the PVC and bamboo
frames. In total 2160 seagrass sprigs were tied (Fig. 3) at a rate
of 120 seagrass sprigs/m2, similar to PVC and Bamboo frames.
The whole unit was fixed on the sea floor using “U” shaped
iron clamps. The total number of five and half coir frames were
used to cover 100 m2 area.
Cost/m2 is an important factor for determining long-term
implementation and replication of any seagrass rehabilitation
methods in community-based projects. In this study the cost, from
sourcing materials and fabrication up to installation of the frames in
the seabed was estimated for each method on a 100 m2 area basis.
The cost estimates did not include expenses related to transport,
scuba diving and monitoring. Of the total 300 m2 nets and frames
thus installed at the seabed, 5 randomly selected frames (5 m2 area)
each of PVC, bamboo and coir nets were monitored in 3rd, 5th and
7th months by scuba diving, recorded percentage cover (%), shoot
density and invertebrate macro fauna in each frame. Environmental
Fig. 3. Seagrass sprigs are being tied by fishermen in coir net frames Fig. 4. Environmental parameters of seagrass restoration site
Fig. 2. Preparation of bamboo frames with jute ropes by fishermen
Journal of the Marine Biological Association of India Vol. 62, No.1, January-June 2020
V. Balaji
et al.
98
Fig. 7. Mean Shoot Density of sea grasses/m2 within PVC, Bamboo and
Coir frames
Fig. 8. Expenditure for the three seagrass restoration methods per 100 m2
Fig. 6. Seagrass percentage cover/m2 within PVC, Bamboo and Coir frames.
Fig. 5. Nutrient parameters of seagrass restoration site
Table 1. Macro faunal density recorded in PVC, bamboo and coir sites in 3rd, 5th and 7th months of the experiment.
Macro fauna PVC Site Bamboo Site Coir Site
3rd 5th 7th 3rd 5th 7th 3rd 5th 7th
Gastropods 0.9±0.05 0.9±0.04 1.2±0.03 1±0.04 0.5±0.02 1.5±0.04 0.2±0.03 1.6±0.04 0.9±0.02
Bivalves 0.6±0.02 1.2±0.05 1.8±0.08 0.8±0.02 1.3±0.03 1.2±0.04 0.1±0.02 1.8±0.06 2.2±0.05
Sponges 0.5±0.02 1.4±0.04 2.1±0.02 0.6±0.02 1.2±0.04 2.1±0.05 0 1.2±0.05 1.8±0.05
Echinoderms 0.3±0.01 0.5±0.02 1.2±0.06 1.2±0.06 0.2±0.02 0.8±0.03 0 0.9±0.02 2±0.05
Coelenterates 0.8±0.02 1.3±0.04 1.3±0.05 0.5±0.03 0 1.6±0.02 0.1±0.02 0 2.6±0.05
Crustaceans 1.2±0.04 1.2±0.04 1.8±0.03 0.1±0.02 0 1.4±0.05 0.3±0.02 1.8±0.06 1.9±0.05
was optimum conditions for seagrass growth and no huge
variation in environmental parameters.
The key difference between the three methods was the usage of
different materials (frames) to keep the seagrass rhizomes close to
the seafloor. The focus of this study being mainly finding the low
cost, eco-friendly frame materials as alternative to PVC frames, it
is important to consider the cost of each method for deciding upon
large scale implementation of seagrass transplantation in future.
The difference in expenditure between the three seagrass frame
methods is significant due to variation in labour and material cost
per 100 m2 area (Fig. 8). In the case of bamboo frame, the material
cost was 46% lesser than that of the PVC frame. The material cost
for coir frame was 63% lesser than the bamboo frame and 102%
lesser than that of the PVC frame. The labour cost for bamboo
frame was 47% lesser than the PVC frame. In the case of coir
frame, it was 14% higher than the bamboo frame, but 33% lower
than the PVC frame. Additional cost was incurred for retrieving
PVC frames, a non-biodegradable material that may possibly
release during its slow breakdown some chemicals harmful for
the restored sea grass system, while the bamboo and coir frames
being biodegradable were left permanently on the seafloor.
No significant difference could be found in seagrass growth
(percentage cover and shoot density) among the 3 different
© Marine Biological Association of India
Comparison of seagrass restoration methods adopted in Palk Bay
99
seagrass experimental methods, as seen from the Chi-Square
test, done between the seagrass growth in PVC, Bamboo and
Coir frames on one to one basis. There was no significant
difference between the percentage cover of sea grasses
between PVC site and Bamboo site (
x
2 (4) = 6; p <0.199).
Similar non-significant differences were seen between Coir
and PVC plots in shoot density and percentage cover as well.
This indicates that material of the frames does not have any
impact on the establishment of seagrass in the sea bed. The
correlation coefficients obtained between nutrients, macro
fauna and environmental parameters were non-significant.
Pollution from plastic and its additives are considered as a threat
to human health (Meeker
et al.
, 2009) and environment (Ruddle,
1982). However, PVC frames for seagrass transplantation was
already carried out in Gulf of Mannar (Patterson and Dsouza,
2015). In the present study, effort was made to remove the
PVC frames after 7th month and 89% of PVC frames were
recovered, the rest could not be recovered due to the dense
growth of restored seagrass. Recovery of PVC frame for reuse
was an additional effort which lead to partial damaging of the
rhizomes. No efforts to examine the pollution impacts of such
plastics left in the restoration sites were reported from any other
seagrass restoration projects. Bamboo frames and tubes were
tested in Thailand for eco-friendly transplantation. In the present
study, bamboo frames were found significantly of low-cost than
PVC frames and moreover, if left on the seafloor they would
slowly decompose and be covered by restored sea grasses.
The present study has used coconut coir nets for the first time
in the world for seagrass transplantation. The key advantage
of using coconut coir nets is that they are locally available in
coastal areas around the world (Mitra, 2018). The coir ropes are
flexible, light weight and local communities can easily prepare
them for seagrass restoration much easily than PVC frames.
This study observed more macrofauna settlements in coir plots
than bamboo and PVC frames. Coir nets can be tied with large
number of seagrass sprigs quickly within a short time by local
communities and needs lesser scuba diving for recovery and
associated works. Thus, it cuts the cost of materials and technical
manpower. Most importantly, the material cost of coir net is the
lowest of all the three methods. However, coconut coir nets have
also some limitations. Due to their positive buoyancy during the
initial days of seagrass transplantation, they tend to float; but
that can be avoided by keeping them submerged in water for 3
days before installing in the field. The cost of bamboo frames is
higher than coir nets. Thus, naturally degradable bamboo and
coir nets are better suited for eco-friendly seagrass restoration,
in which coconut coir method is the best as it is relatively low
cost, easily available and suitable for large scale, community-
based seagrass restoration. There is a need to continue this
research in testing bamboo, coir and other degradable frames
at various depths and seasons. However, as of now looking at
the finding of the study it is recommended to preferably use
coconut coir frames and then bamboo frames for large scale,
low cost, eco-friendly seagrass transplantation.
Acknowledgements
Authors thank Thanjavur and Pudukkottai District Forest Offices
of Tamil Nadu Forest Department for providing financial support
for seagrass transplantation under Tamil Nadu Biodiversity and
Greening Project. Authors also thank Dr. P. A. Azeez, Former
Director of SACON for the comments on the manuscript.
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Mangrove–coral habitat is characterized by heterogeneity in the physical environment that allows it to be out of equilibrium with open ocean conditions, resulting in differentiation of local physical, chemical, and biological attributes. This chapter highlights how some mangrove habitats can act as alternate refuges for corals during climate threats, particularly increasing seawater temperature, high levels of solar radiation, and ocean acidification. Coastal ecosystems are interconnected and so any change in one coastal ecosystem will have an impact on other ecosystems. Similarly, recovery and resilience of coastal ecosystems like coral reefs depend on the degree of connectivity and support from the neighboring coastal ecosystems such as seagrass beds. Therefore, healthy seagrass beds are especially vital for the resilience of coral reefs, as they support the coral communities to adapt to climate change impacts. Corals compete with seaweeds for space on the reef. When corals are healthy, the coral–seaweed competition reaches a balance. But, if the corals are not able to do well because of smothering like eutrophication or climate change induced impacts, then seaweeds can take over. Our study results suggest that coral reefs may become increasingly susceptible to seaweed proliferation under ocean acidification. Though the functional links of mangroves, seagrasses, and coral reefs have been studied, their conservation and management aspects due to connectivity and their importance for humans is yet to be understood. Importance of interconnectivity in biodiversity richness is illustrated by presenting the bioresource availability in the existing heterogeneous coral reef, seagrass, and mangrove habitats of the Neil Island, the Andamans and studies on the interactions among them are essential for conservation and management of such precious ecosystems.
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A study was conducted during March 2018 at Shantiniketan (in the Birbhum District of West Bengal) on the biomass and stored carbon in the vegetative parts (trunks and leaves) of coconut tree in three separate patches of study site. The above ground carbon seems to be a direct function of the above ground biomass of the species. Analyses of the leaves and trunk wood for carbon percentage through CHN analyser exhibited relatively higher percentage of stored carbon in the dried leaves (48.1 %-48.7 %) compared to the trunk wood (45.9 %-46.3 %). The range of biomass of the species in the present study varies between 100.02 tha-1 to 226.45 tha-1 , which has stored carbon between 47.01 tha-1 to 107.60 tha-1 in the Sristi Baganbari, Kamarpara in the Birbhum district of West Bengal. This confirms the species as potential sink of carbon and is an important regulatory ecosystem service in addition to other services.
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Present study consists the acoustic survey of sea grass beds carried out in 220 sq.km along the coast of northern Palk Bay. In total 865,440 acoustic pings were recorded along the transects. The study showed that the seagrass beds spread along the shore of Thanjavur district in Tamil Nadu up to 12,243 hectares reaching up to eight kilometers from the coast and 8 m depth. Seven species of seagrasses were found in the area. Of these, Cymodocea serrulata was the dominant species, which occupies a depth ranging between 2 m and 5 m. Shoreward edge of the seagrass meadow was not in healthy condition showing physical damages and wide algal cover. Seaward edge of the meadow was dense and probably feeding ground for dugongs. © 2018, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.
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Land-use change in the coastal zone has led to worldwide degradation of marine coastal ecosystems and a loss of the goods and services they provide. Restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed and is critical for habitats where natural recovery is hindered. Uncertainties about restoration cost and feasibility can impede decisions on whether, what, how, where, and how much to restore. Here, we perform a synthesis of 235 studies with 954 observations from restoration or rehabilitation projects of coral reefs, seagrass, mangroves, saltmarshes, and oyster reefs worldwide, and evaluate cost, survival of restored organisms, project duration, area, and techniques applied. Findings showed that while the median and average reported costs for restoration of one hectare of marine coastal habitat were around US$80 000 (2010) and US$1 600 000 (2010), respectively, the real total costs (median) are likely to be two to four times higher. Coral reefs and seagrass were among the most expensive ecosystems to restore. Mangrove restoration projects were typically the largest and the least expensive per hectare. Most marine coastal restoration projects were conducted in Australia, Europe, and USA, while total restoration costs were significantly (up to 30 times) cheaper in countries with developing economies. Community-or volunteer-based marine restoration projects usually have lower costs. Median survival of restored marine and coastal organisms, often assessed only within the first one to two years after restoration, was highest for saltmarshes (64.8%) and coral reefs (64.5%) and lowest for seagrass (38.0%). However, success rates reported in the scientific literature could be biased towards publishing successes rather than failures. The majority of restoration projects were short-lived and seldom reported monitoring costs. Restoration success depended primarily on the ecosystem, site selection, and techniques applied rather than on money spent. We need enhanced investment in both improving restoration practices and large-scale restoration. © 2016 The Authors Ecological Applications published by Wiley Periodicals, Inc.
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Seagrasses are marine flowering plants and one of the ecologically sensitive habitats. The Gulf of Mannar and Palk Bay in southeastern India have luxuriant seagrass beds with rich associated biodiversity, in particular fishery resources. Thousands of traditional fisher folk of Gulf of Mannar and Palk Bay depend on seagrass ecosystem for livelihood. The diversity, distribution and abundance of seagrasses was assessed in 2 these low coastal areas during 2007-2008. The total seagrass cover in Gulf of Mannar Marine National Park was 76 Km and in Palk Bay (Pamban 2 to Thondi) it was 175 Km . Thalassia hemprichii and Cymodocea serrulata are the dominant seagrass species in both areas. In Gulf of Mannar, seagrass abundance was comparably high in the shoreward side of the islands and in Palk Bay, and a high density was noted in the middle zone (3-6 km from the shore). The present assessment aimed at collecting comprehensive baseline data, which will be helpful to conduct further monitoring and to implement management measures including restoration activities in order to effectively conserve the resources for sustainable utilization.
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Seagrass restoration has often not been successful due to poor site planning, physical disturbance, transplant timing incompatibility, and physical and biological disturbances. As such, these factors are important for successfully restoring seagrasses, and global success has greatly increased. We conducted restorations in the mid-Atlantic region of the United States to reestablish this valuable habitat. Our restoration efforts in New Jersey involved transplants of both Zostera marina (eelgrass) and Ruppia maritima (widgeon grass). We found that Z. marina site success and transplant survival increased over the scope of this 4-year investigation (66%–100% and 34%–43%, respectively). However, R. maritima success was heavily dependant upon the year planted; with limited success in 2002 (12%) and high success during 2003 (80%), most likely related to the brown-tide bloom and nonbloom associated with these planting years. For both species restored, ecosystem function was becoming established by the end of the study, demonstrated by their ability to trap and bind fine particulate matter. We provide evidence from this study that seagrass restoration is a viable option for coastal managers and that once established, seagrasses can recover and expand.
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More than 50% of eelgrass habitats have disappeared from the Swedish NW coast in the last 30 years. Restoration is being proposed to assist recovery but little is known regarding methods suitable under Scandinavian conditions; e.g. short growing seasons and scouring by ice. In the present study we evaluated different restoration methods using shoots and seeds in a Swedish fjord and assessed if eelgrass could be successfully transplanted between sites with different depth and exposure. The study demonstrates that both shoot- and seed methods can be successfully used to restore eelgrass at this latitude. Survival and growth of unanchored single shoots, transplanted without sediment in shallow habitats (1.0–1.5 m) was very high (> 500% increase in shoot density after 14 months). This restoration method showed 2–3.5 times higher growth rate and was 2–2.5 times faster compared with shoots anchored in the sediment and shoots transplanted in sediment cores, respectively, and is recommended for shallow habitats in Sweden. Growth within deeper habitats (3.0–4.5 m) was substantially lower (40% loss to 50% increase) due to light limitations and high winter mortality. Restoration using seeds distributed from mesh-bags showed very low seedling establishment rates (approximately 1%) making this method less cost-effective than transplanting single shoots in shallow habitats. However, growth of seedlings was high and this method is recommended for deep habitats with soft sediment where shoot transplantation is difficult. Despite dramatic differences in eelgrass morphology between habitats with different depth and exposure, all shoots within a planting site had the same morphology at the end of the study, independent of origin. A baseline genetic survey supported that the observed changes in morphology of transplants were due to a plastic response, suggesting that donor populations do not have to exactly match the morphology of the plants targeted for restoration.
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Conservation biology and restoration ecology share a common interest in maintaining or enhancing populations, communities, and ecosystems. Much could be gained by more closely integrating the disciplines, but several challenges stand in the way. Goals differ, reflecting different origins and agendas. Because resources are insufficient to meet all needs, priorities must be established. Rapid environmental changes create uncertainties that compromise goals and priorities. To realize the benefits of integration, goals should be complementary, acknowledging the uncertainties that stem from temporal and spatial dynamics. Priorities should be established using clearly defined criteria, recognizing that not everything can be conserved or restored; some form of triage is inevitable. Because goals and priorities are societal concerns, conservation and restoration must include people as part of—rather than separate from—nature. A more meaningful and integrated approach will blur disciplinary boundaries, focus on outcomes rather than approaches, and use the tools of both disciplines.
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Small isolated oceanic islands are renowned for endemic species and biological wealth. Many small island administrations all over the world face complex challenges in protecting their natural resources. Restoration of degraded ecosystems is the best way to bring the coastal habitats to their previous forms. In the present study, seagrass restoration sites in six islands of Lakshadweep were selected using satellite map, GIS tools and field observations. Seagrass-denuded areas were identified integrating the classified seagrass maps of the years 2000 and 2008. Specific criteria and buffer zones were generated to delineate the restoration sites. A total area of 156.21 ha is identified for seagrass restoration, distributed in the six islands. These areas can be given priority for the seagrass restoration as it will avoid the conflict of rising transplants in newer areas where seagrasses do not exist.