scholarly journals Sponge bioerosion and habitat degradation on Indonesian coral reefs

2021 ◽  
Author(s):  
◽  
Joseph Marlow
Keyword(s):  
Coral Reefs ◽  
Habitat Degradation ◽  
Sponge Species ◽  
Environmental Drivers ◽  
Light Limitation ◽  
Sponge Tissue ◽  
Assemblage Composition ◽  
Larval Recruitment ◽  
Reef Degradation ◽  
The Common

<p>Coral reefs are among the most diverse ecosystems on the planet, yet they are also sensitive to anthropogenic disturbances that can degrade these systems. On many degraded reefs, large increases in bioeroding sponge abundance have occurred. On healthy reefs these sponges contribute to species diversity and habitat complexity, however there is growing concern that their proliferation on degraded reefs could lead to a state of net-erosion. In the Southeast Asian Indo-Pacific, the ecology of bioeroding sponges in relation to coral degradation has been poorly studied compared to other coral reef regions. This thesis aims to increase our understanding of the ecology of these sponges in the Wakatobi region of Indonesia, and their likely trajectory if reefs continue to degrade in the region.  My first research chapter aimed to identify the common bioeroding sponge species of the Wakatobi. This was achieved through in-water surveys, and subsequent spicule and phylogenetic analysis. This resulted in the identification of eight commonly occurring Wakatobi bioeroding sponge species, two of which are described for the first time. The assemblage composition was distinctly different from the only other bioeroding sponge study in Indonesian waters (Calcinai et al. 2005), highlighting the need for more clionaid taxonomic information from the region.  Having identified the common bioeroding sponge species in the region, my second chapter assessed the major environmental drivers of the abundance and assemblage composition of these sponges. Abundance surveys were conducted at 11 reef sites characterised by different environmental conditions and states of reef health. Bioeroding sponges occupied 8.9% of suitable substrate, and differences in abundance and assemblage composition were primarily attributed to differences in the availability of dead substrate. However, abundance was lowest at a sedimented and turbid reef, despite abundant dead substrate availability. This indicates a limited resilience in some species to conditions associated with terrestrial run-off and that not all forms of reef degradation are beneficial for bioeroding sponges. The capacity to increase spatial occupation of degraded reefs is also dependent upon larval recruitment and my third chapter was a two year recruitment study using in situ experimental calcareous blocks. Recruitment occurred rapidly and consistently with bioeroding sponges recruiting to approximately 70% of experimental blocks and exhibiting a preference for settlement on uncolonised dead calcareous substrates. The importance of substrate settlement cues and extent of larval dispersal appeared to differ between species, indicative of different recruitment mechanisms. Any significant increase in the availability of exposed calcareous substrate (e.g. following a mass coral bleaching event) is therefore likely to result in widespread increases in bioeroding sponge recruitment.  Surveys conducted in my second research chapter revealed that two of the three locally abundant zooxanthellate bioeroding species were absent from a highly turbid reef, Sampela. My fourth research chapter investigated whether this was due to light limitation by examining the photoacclimatory capabilities of the Symbiodinium photosymbionts of Cliona aff. viridis n. sp. A. PAM chlorophyll fluorometry was employed in a 25 day shading experiment and Symbiodinium of C. aff. viridis n. sp. A demonstrated an ability to photoacclimate to extreme light reduction and recover quickly when conditions returned to normal. My results demonstrate that the absence of this species at Sampela is not due to light limitation but possibly due to other stressors associated with turbidity, e.g. suspended sediment.  My final chapter was an assessment of the environmental drivers of rates of bioerosion in Spheciospongia cf. vagabunda, a common species in the Wakatobi. Erosion rates were determined from changes in dry-weight of calcareous substrates with attached grafts of S. cf. vagabunda after a year deployment across seven reef sites. The average bioerosion rate was 12.0 kg m⁻² sponge tissue yr⁻¹ (± 0.87 SE), but differed between sites and was negatively correlated with settled sediment depth. Bioerosion by this species can play a significant part in the carbonate budget on reefs where it is abundant (up to 20% of available substrate on some reefs in the Wakatobi) but is likely reduced on highly sedimented reefs.  In summary, the Wakatobi bioeroding sponge assemblage is diverse and overall, both adult abundance and recruitment are primarily driven by the availability of dead calcareous substrates. Therefore, further coral mortality and a subsequent rise in the availability of dead substrate in the region is likely to result in increased abundance of bioeroding sponges. However, not all forms of reef degradation will benefit these sponges; turbid and sedimented reefs will likely constitute stressful habitats for some bioeroding sponge species and assemblages in these environments will be comprised of fewer more resilient species.</p>

scholarly journals Sponge bioerosion and habitat degradation on Indonesian coral reefs

2021 ◽  
Author(s):  
◽  
Joseph Marlow
Keyword(s):  
Coral Reefs ◽  
Habitat Degradation ◽  
Sponge Species ◽  
Environmental Drivers ◽  
Light Limitation ◽  
Sponge Tissue ◽  
Assemblage Composition ◽  
Larval Recruitment ◽  
Reef Degradation ◽  
The Common

<p>Coral reefs are among the most diverse ecosystems on the planet, yet they are also sensitive to anthropogenic disturbances that can degrade these systems. On many degraded reefs, large increases in bioeroding sponge abundance have occurred. On healthy reefs these sponges contribute to species diversity and habitat complexity, however there is growing concern that their proliferation on degraded reefs could lead to a state of net-erosion. In the Southeast Asian Indo-Pacific, the ecology of bioeroding sponges in relation to coral degradation has been poorly studied compared to other coral reef regions. This thesis aims to increase our understanding of the ecology of these sponges in the Wakatobi region of Indonesia, and their likely trajectory if reefs continue to degrade in the region.  My first research chapter aimed to identify the common bioeroding sponge species of the Wakatobi. This was achieved through in-water surveys, and subsequent spicule and phylogenetic analysis. This resulted in the identification of eight commonly occurring Wakatobi bioeroding sponge species, two of which are described for the first time. The assemblage composition was distinctly different from the only other bioeroding sponge study in Indonesian waters (Calcinai et al. 2005), highlighting the need for more clionaid taxonomic information from the region.  Having identified the common bioeroding sponge species in the region, my second chapter assessed the major environmental drivers of the abundance and assemblage composition of these sponges. Abundance surveys were conducted at 11 reef sites characterised by different environmental conditions and states of reef health. Bioeroding sponges occupied 8.9% of suitable substrate, and differences in abundance and assemblage composition were primarily attributed to differences in the availability of dead substrate. However, abundance was lowest at a sedimented and turbid reef, despite abundant dead substrate availability. This indicates a limited resilience in some species to conditions associated with terrestrial run-off and that not all forms of reef degradation are beneficial for bioeroding sponges. The capacity to increase spatial occupation of degraded reefs is also dependent upon larval recruitment and my third chapter was a two year recruitment study using in situ experimental calcareous blocks. Recruitment occurred rapidly and consistently with bioeroding sponges recruiting to approximately 70% of experimental blocks and exhibiting a preference for settlement on uncolonised dead calcareous substrates. The importance of substrate settlement cues and extent of larval dispersal appeared to differ between species, indicative of different recruitment mechanisms. Any significant increase in the availability of exposed calcareous substrate (e.g. following a mass coral bleaching event) is therefore likely to result in widespread increases in bioeroding sponge recruitment.  Surveys conducted in my second research chapter revealed that two of the three locally abundant zooxanthellate bioeroding species were absent from a highly turbid reef, Sampela. My fourth research chapter investigated whether this was due to light limitation by examining the photoacclimatory capabilities of the Symbiodinium photosymbionts of Cliona aff. viridis n. sp. A. PAM chlorophyll fluorometry was employed in a 25 day shading experiment and Symbiodinium of C. aff. viridis n. sp. A demonstrated an ability to photoacclimate to extreme light reduction and recover quickly when conditions returned to normal. My results demonstrate that the absence of this species at Sampela is not due to light limitation but possibly due to other stressors associated with turbidity, e.g. suspended sediment.  My final chapter was an assessment of the environmental drivers of rates of bioerosion in Spheciospongia cf. vagabunda, a common species in the Wakatobi. Erosion rates were determined from changes in dry-weight of calcareous substrates with attached grafts of S. cf. vagabunda after a year deployment across seven reef sites. The average bioerosion rate was 12.0 kg m⁻² sponge tissue yr⁻¹ (± 0.87 SE), but differed between sites and was negatively correlated with settled sediment depth. Bioerosion by this species can play a significant part in the carbonate budget on reefs where it is abundant (up to 20% of available substrate on some reefs in the Wakatobi) but is likely reduced on highly sedimented reefs.  In summary, the Wakatobi bioeroding sponge assemblage is diverse and overall, both adult abundance and recruitment are primarily driven by the availability of dead calcareous substrates. Therefore, further coral mortality and a subsequent rise in the availability of dead substrate in the region is likely to result in increased abundance of bioeroding sponges. However, not all forms of reef degradation will benefit these sponges; turbid and sedimented reefs will likely constitute stressful habitats for some bioeroding sponge species and assemblages in these environments will be comprised of fewer more resilient species.</p>

Importance of philopatry and hydrodynamics in the recruitment of bioeroding sponges on Indonesian coral reefs

2019 ◽  
Vol 70 (6) ◽  
pp. 755
Author(s):  
Joseph Marlow ◽  
Abdul Haris ◽  
James Bell
Keyword(s):  
Coral Reefs ◽  
Large Scale ◽  
Species Assemblage ◽  
Coral Mortality ◽  
Factors Affecting ◽  
Larval Recruitment ◽  
Spatial Coverage ◽  
Reef Degradation ◽  
Adult Abundance ◽  
Cliona Orientalis

Increasingly frequent large-scale coral mortality events are occurring across the globe, leading to a rise in available reef substrata and promoting an increase in the abundance of other benthic taxa. One such group are bioeroding sponges, which can benefit considerably from reef degradation. However, the occupation of new substrates is partially reliant upon larval recruitment, and currently little is known about the factors affecting bioeroding sponge recruitment. In this study we investigated the potential drivers of bioeroding sponge recruitment using a 2-year deployment of experimental calcareous substrates across seven reefs in the Wakatobi region of Indonesia. Recruitment was observed for five bioeroding sponge species, namely Cliona orientalis, Cliothosa cf. aurivillii, Cliothosa hancocki and two presently unidentified brown clionaids, Cliona aff. viridis sp. A and Cliona aff. viridis sp. B. Recruits were present on 69% of the experimental substrates but had a low mean (±s.e.m.) spatial coverage of just 0.42±0.13%. Total recruitment and species assemblage structure were correlated with local adult abundance, water flow and substrate cues. Our results suggest that any proliferation of bioeroding sponges on newly available substrate following coral mortality is likely to be conditional on local adult abundance and hydrodynamics.

scholarly journals A Deep-Sea Sponge Loop? Sponges Transfer Dissolved and Particulate Organic Carbon and Nitrogen to Associated Fauna

2021 ◽  
Vol 8 ◽  
Author(s):  
Martijn C. Bart ◽  
Meggie Hudspith ◽  
Hans Tore Rapp ◽  
Piet F. M. Verdonschot ◽  
Jasper M. de Goeij
Keyword(s):  
Organic Matter ◽  
Coral Reefs ◽  
Shallow Water ◽  
Deep Sea ◽  
Cold Water ◽  
Trophic Levels ◽  
Sponge Species ◽  
Sponge Tissue ◽  
Associated Fauna ◽  
Brittle Stars

Cold-water coral reefs and sponge grounds are deep-sea biological hotspots, equivalent to shallow-water tropical coral reefs. In tropical ecosystems, biodiversity and productivity are maintained through efficient recycling pathways, such as the sponge loop. In this pathway, encrusting sponges recycle dissolved organic matter (DOM) into particulate detritus. Subsequently, the sponge-produced detritus serves as a food source for other organisms on the reef. Alternatively, the DOM stored in massive sponges was recently hypothesized to be transferred to higher trophic levels through predation of these sponges, instead of detritus production. However, for deep-sea sponges, the existence of all prerequisite, consecutive steps of the sponge loop have not yet been established. Here, we tested whether cold-water deep-sea sponges, similar to their tropical shallow-water counterparts, take up DOM and transfer assimilated DOM to associated fauna via either detritus production or predation. We traced the fate of 13carbon (C)- and 15nitrogen (N)-enriched DOM and particulate organic matter (POM) in time using a pulse-chase approach. During the 24-h pulse, the uptake of 13C/15N-enriched DOM and POM by two deep-sea sponge species, the massive species Geodia barretti and the encrusting species Hymedesmia sp., was assessed. During the subsequent 9-day chase in label-free seawater, we investigated the transfer of the consumed food by sponges into brittle stars via two possible scenarios: (1) the production and subsequent consumption of detrital waste or (2) direct feeding on sponge tissue. We found that particulate detritus released by both sponge species contained C from the previously consumed tracer DOM and POM, and, after 9-day exposure to the labeled sponges and detritus, enrichment of 13C and 15N was also detected in the tissue of the brittle stars. These results therefore provide the first evidence of all consecutive steps of a sponge loop pathway via deep-sea sponges. We cannot distinguish at present whether the deep-sea sponge loop is acting through a detrital or predatory pathway, but conclude that both scenarios are feasible. We conclude that sponges could play an important role in the recycling of DOM in the many deep-sea ecosystems where they are abundant, although in situ measurements are needed to confirm this hypothesis.

Dispersal and association of two alien species in the Indonesian coral reefs: the octocoral Carijoa riisei and the demosponge Desmapsamma anchorata

2004 ◽  
Vol 84 (5) ◽  
pp. 937-941 ◽  
Author(s):  
B. Calcinai ◽  
G. Bavestrello ◽  
C. Cerrano
Keyword(s):  
Coral Reefs ◽  
Alien Species ◽  
Sponge Tissue ◽  
Branching Pattern ◽  
Indonesian Population ◽  
Morphological Adaptations ◽  
Carijoa Riisei ◽  
Pacific Area

The discovery of the association between the sponge Desmapsamma anchorata (Demospongiae: Poecilosclerida: Desmacididae) and the octocoral Carijoa riisei (Cnidaria: Alcyonacea: Clavularidae) on an Indonesian reef enlarges the widespread dispersion of these Atlantic species in the Indo-Pacific area. The species involved and their morphological adaptations resulting from the association are described. When covered by the sponge, C. riisei develops an irregular branching pattern and a dense nematocyst layer where the ectoderm comes in contact with the sponge tissue. The finding of fertile colonies suggests that the Indonesian population of C. riisei is self-sustaining.

scholarly journals Status and conservation of the giant muntjac Megamuntiacus vuquangensis, and notes on other muntjac species in Laos

Oryx ◽  
1998 ◽  
Vol 32 (1) ◽  
pp. 59-67 ◽  
Author(s):  
R. J. Timmins ◽  
T. D. Evans ◽  
Khamkhoun Khounboline ◽  
Chainoi Sisomphone
Keyword(s):  
Habitat Degradation ◽  
Range Limits ◽  
Restricted Range ◽  
Taxonomic Affinity ◽  
Red Data Book ◽  
Wide Range ◽  
Data Book ◽  
The Common ◽  
Near Future ◽  
Muntiacus Muntjak

The large-antlered, or giant, muntjac Megamuntiacus vuquangensis wasdescribed from Vietnam in 1994 and found concurrently in the Annamite Mountains and nearby hill ranges of central and southern Laos. The northerly and southerly range limits are still unknown. It may occupy a wide range of habitats and is found sympatrically with the common muntjac Muntiacus muntjak. Another muntjac species, the taxonomic affinity of which is as yet undetermined, was recently discovered to occur within its range. The large-antlered muntjac is probably not threatened with extinction in the near future, but in view of its restricted range and threats from habitat degradation and hunting, it should be classified as Vulnerable in the Red Data Book. Its future in Laos is largely dependent on the recently created protected-areas system to maintain large tracts of habitat and reduce hunting pressure.

scholarly journals Latitudinal patterns in intertidal ecosystem structure in West Greenland suggest resilience to climate change

2021 ◽  
Author(s):  
Jakob Thyrring ◽  
Susse Wegeberg ◽  
Martin E Blicher ◽  
Dorte Krause-Jensen ◽  
Signe H&oslashgslund ◽  
...  
Keyword(s):  
Climate Change ◽  
Ascophyllum Nodosum ◽  
Tidal Range ◽  
Environmental Drivers ◽  
Small Scale ◽  
Ecosystem Structure ◽  
Assemblage Composition ◽  
West Greenland ◽  
Functional Changes ◽  
Time Substitution

Climate change has ecosystem-wide cascading effects. Little is known, however, about the resilience of Arctic marine ecosystems to environmental change. Here we quantify and compare large-scale patterns in rocky intertidal biomass, coverage and zonation in six regions along a north-south gradient of temperature and ice conditions in West Greenland (60-72°N). We related the level and variation in assemblage composition, biomass and coverage to latitudinal-scale environmental drivers. Across all latitudes, the intertidal assemblage was dominated by a core of stress-tolerant foundation species that constituted >95% of the biomass. Hence, canopy-forming macroalgae, represented by Fucus distichus subsp. evanescens and F. vesiculosus and, up to 69 °N, also Ascophyllum nodosum, together with Semibalanus balanoides, occupied >70% of the vertical tidal range in all regions. Thus, a similar functional assemblage composition occurred across regions, and no latitudinal depression was observed. The most conspicuous difference in species composition from south to north was that three common species (the macroalgae Ascophyllum nodosum, the amphipod Gammarus setosus and the gastropod Littorina obtusata) disappeared from the mid-intertidal, although at different latitudes. There were no significant relationships between assemblage metrics and air temperature or sea ice coverage as obtained from weather stations and satellites, respectively. Although the mean biomass decreased >50% from south to north, local biomass in excess of 10 000 g ww m-2 was found even at the northernmost site, demonstrating the patchiness of this habitat and the effect of small-scale variation in environmental characteristics. Hence, using the latitudinal gradient in a space-for-time substitution, our results suggest that while climate modification may lead to an overall increase in the intertidal biomass in north Greenland, it is unlikely to drive dramatic functional changes in ecosystem structure in the near future. Our dataset provides an important baseline for future studies to verify these predictions for Greenlands intertidal zone.

Bioeroding sponge assemblages: the importance of substrate availability and sediment

2018 ◽  
Vol 99 (2) ◽  
pp. 343-358 ◽  
Author(s):  
Joseph Marlow ◽  
Christine H.L. Schönberg ◽  
Simon K. Davy ◽  
Abdul Haris ◽  
Jamaluddin Jompa ◽  
...  
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Sponge Species ◽  
Coral Mortality ◽  
Substrate Availability ◽  
Abiotic Conditions ◽  
Assemblage Composition ◽  
Reef Health

Despite global deterioration of coral reef health, not all reef-associated organisms are in decline. Bioeroding sponges are thought to be largely resistant to the factors that stress and kill corals, and are increasing in abundance on many reefs. However, there is a paucity of information on how environmental factors influence spatial variation in the distribution of these sponges, and how they might be affected by different stressors. We aimed to identify the factors that explained differences in bioeroding sponge abundance and assemblage composition, and to determine whether bioeroding sponges benefit from the same environmental conditions that can contribute towards coral mortality. Abundance surveys were conducted in the Wakatobi region of Indonesia on reefs characterized by different biotic and abiotic conditions. Bioeroding sponges occupied an average of 8.9% of available dead substrate and variation in abundance and assemblage composition was primarily attributed to differences in the availability of dead substrate. Our results imply that if dead substrate availability increases as a consequence of coral mortality, bioeroding sponge abundance is also likely to increase. However, bioeroding sponge abundance was lowest on a sedimented reef, despite abundant dead substrate. This suggests that not all forms of coral mortality will benefit all bioeroding sponge species, and sediment-degraded reefs are likely to be dominated by a few resilient bioeroding sponge species. Overall, we demonstrate the importance of understanding the drivers of bioeroding sponge abundance and assemblage composition in order to predict possible impacts of different stressors on reefs communities.

An update on the diversity of marine sponges in the southern gulf of Mexico coral reefs

Zootaxa ◽  
2021 ◽  
Vol 5031 (1) ◽  
pp. 1-112
Author(s):  
DIANA UGALDE ◽  
JULIO C.C. FERNANDEZ ◽  
PATRICIA GÓMEZ ◽  
GISELE LÔBO-HAJDU ◽  
NUNO SIMÕES
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Gulf Of Mexico ◽  
New Records ◽  
Marine Sponges ◽  
Sponge Species ◽  
Southern Gulf Of Mexico

Until now, 127 species of marine sponges have been recorded in the southern Gulf of Mexico (SGoM). In this study, we describe the sponge fauna recorded on 16 coral reefs of the SGoM, defined as the Mexican waters of the Gulf of Mexico (GoM), during a period from 2005 to 2019. We report 80 sponge species, including 34 first geographic records for the southern GoM region. The latter are fully described and illustrated, taking into account 24 that represent new records for the GoM: Agelas conifera, Agelas sventres, Agelas wiedenmayeri, Prosuberites carriebowensis, Desmanthus meandroides, Cliona aprica, Cliona dioryssa, Placospongia ruetzleri, Haliclona (Gellius) megasclera, Haliclona (Reniera) aff. portroyalensis, Neopetrosia proxima, Xestospongia arenosa, Calyx podatypa, Shiphonodictyon xamaycaense, Acarnus innominatus, Iotrochota arenosa, Polymastia tenax, Svenzea cristinae, Svenzea flava, Svenzea tubulosa, Svenzea zeai, Timea stenosclera, Stellettinopsis megastylifera, Suberea flavolivescens. The present work highlights the understimated and remarkable diversity of reef-associated sponges within the Campeche Bank Coral reef systems. Present work data was compiled with existing published information to produce an updated list of 161 known sponges in the southern GoM.  

scholarly journals Deep-sea sponge grounds as nutrient sinks: denitrification is common in boreo-Arctic sponges

2020 ◽  
Vol 17 (5) ◽  
pp. 1231-1245 ◽  
Author(s):  
Christine Rooks ◽  
James Kar-Hei Fang ◽  
Pål Tore Mørkved ◽  
Rui Zhao ◽  
Hans Tore Rapp ◽  
...  
Keyword(s):  
Deep Sea ◽  
Cold Water ◽  
Marine Ecosystem ◽  
Sponge Species ◽  
Lag Phase ◽  
Sponge Tissue ◽  
Ammonium Oxidation ◽  
Genes Encoding ◽  
Key Enzyme ◽  
Nutrient Sinks

Abstract. Sponges are commonly known as general nutrient providers for the marine ecosystem, recycling organic matter into various forms of bioavailable nutrients such as ammonium and nitrate. In this study we challenge this view. We show that nutrient removal through microbial denitrification is a common feature in six cold-water sponge species from boreal and Arctic sponge grounds. Denitrification rates were quantified by incubating sponge tissue sections with 15NO3--amended oxygen-saturated seawater, mimicking conditions in pumping sponges, and de-oxygenated seawater, mimicking non-pumping sponges. It was not possible to detect any rates of anaerobic ammonium oxidation (anammox) using incubations with 15NH4+. Denitrification rates of the different sponge species ranged from below detection to 97 nmol N cm−3 sponge d−1 under oxic conditions, and from 24 to 279 nmol N cm−3 sponge d−1 under anoxic conditions. A positive relationship between the highest potential rates of denitrification (in the absence of oxygen) and the species-specific abundances of nirS and nirK genes encoding nitrite reductase, a key enzyme for denitrification, suggests that the denitrifying community in these sponge species is active and prepared for denitrification. The lack of a lag phase in the linear accumulation of the 15N-labelled N2 gas in any of our tissue incubations is another indicator for an active community of denitrifiers in the investigated sponge species. Low rates for coupled nitrification–denitrification indicate that also under oxic conditions, the nitrate used to fuel denitrification rates was derived rather from the ambient seawater than from sponge nitrification. The lack of nifH genes encoding nitrogenase, the key enzyme for nitrogen fixation, shows that the nitrogen cycle is not closed in the sponge grounds. The denitrified nitrogen, no matter its origin, is then no longer available as a nutrient for the marine ecosystem. These results suggest a high potential denitrification capacity of deep-sea sponge grounds based on typical sponge biomass on boreal and Arctic sponge grounds, with areal denitrification rates of 0.6 mmol N m−2 d−1 assuming non-pumping sponges and still 0.3 mmol N m−2 d−1 assuming pumping sponges. This is well within the range of denitrification rates of continental shelf sediments. Anthropogenic impact and global change processes affecting the sponge redox state may thus lead to deep-sea sponge grounds changing their role in marine ecosystem from being mainly nutrient sources to becoming mainly nutrient sinks.

scholarly journals Uncovering the environmental drivers of short-term temporal dynamics in an epibenthic community from the Western English Channel

2019 ◽  
Vol 99 (7) ◽  
pp. 1467-1479
Author(s):  
Elizabeth Talbot ◽  
Jorn Bruggeman ◽  
Chris Hauton ◽  
Stephen Widdicombe
Keyword(s):  
Time Series Data ◽  
Temporal Dynamics ◽  
Anthropogenic Impacts ◽  
Benthic Communities ◽  
Food Limitation ◽  
Environmental Drivers ◽  
Sediment Surface ◽  
Series Data ◽  
English Channel ◽  
Larval Recruitment

AbstractBenthic communities, critical to the health and function of marine ecosystems, are under increasing pressure from anthropogenic impacts such as pollution, eutrophication and climate change. In order to refine predictions of likely future changes in benthic communities resulting from these impacts, we must first better constrain their responses to natural seasonality in environmental conditions. Epibenthic time series data (July 2008–May 2014) have been collected from Station L4, situated 7.25 nautical miles south of Plymouth in the Western English Channel. These data were analysed to establish patterns in community abundance, wet biomass and composition, and to link any observed patterns to environmental variables. A clear response to the input of organic material from phytoplankton blooms was detected, with sediment surface living deposit feeders showing an immediate increase in abundance, while predators and scavengers responded later, with an increase in biomass. We suggest that this response is a result of two factors. The low organic content of the L4 sediment results in food limitation of the community, and the mild winter/early spring bottom water temperatures allow the benthos to take immediate advantage of bloom sedimentation. An inter-annual change in community composition was also detected, as the community shifted from one dominated by the anomuran Anapagurus laevis to one dominated by the gastropod Turitella communis. This appeared to be related to a period of high larval recruitment for T. communis in 2013/2014, suggesting that changes in the recruitment success of one species can affect the structure of an entire community.

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