scholarly journals Disturbance, colonization and development of Antarctic benthic communities

2006 ◽  
Vol 362 (1477) ◽  
pp. 11-38 ◽  
Author(s):  
David K.A Barnes ◽  
Kathleen E Conlan
Keyword(s):  
Temperature Stress ◽  
Benthic Communities ◽  
Larval Abundance ◽  
Indigenous Species ◽  
Benthic Organisms ◽  
Community Recovery ◽  
Sea Floor ◽  
Wind Speeds ◽  
Non Indigenous Species ◽  
The Antarctic

A decade has yielded much progress in understanding polar disturbance and community recovery—mainly through quantifying ice scour rates, other disturbance levels, larval abundance and diversity, colonization rates and response of benthos to predicted climate change. The continental shelf around Antarctica is clearly subject to massive disturbance, but remarkably across so many scales. In summer, millions of icebergs from sizes smaller than cars to larger than countries ground out and gouge the sea floor and crush the benthic communities there, while the highest wind speeds create the highest waves to pound the coast. In winter, the calm associated with the sea surface freezing creates the clearest marine water in the world. But in winter, an ice foot encases coastal life and anchor ice rips benthos from the sea floor. Over tens and hundreds of thousands of years, glaciations have done the same on continental scales—ice sheets have bulldozed the seabed and the zoobenthos to edge of shelves. We detail and rank modern disturbance levels (from most to least): ice; asteroid impacts; sediment instability; wind/wave action; pollution; UV irradiation; volcanism; trawling; non-indigenous species; freshwater inundation; and temperature stress. Benthic organisms have had to recolonize local scourings and continental shelves repeatedly, yet a decade of studies have demonstrated that they have (compared with lower latitudes) slow tempos of reproduction, colonization and growth. Despite massive disturbance levels and slow recolonization potential, the Antarctic shelf has a much richer fauna than would be expected for its area. Now, West Antarctica is among the fastest warming regions and its organisms face new rapid changes. In the next century, temperature stress and non-indigenous species will drastically rise to become dominant disturbances to the Antarctic life. Here, we describe the potential for benthic organisms to respond to disturbance, focusing particularly on what we know now that we did not a decade ago.

scholarly journals Variability in the settlement of non-indigenous species in benthic communities from an oceanic island

2018 ◽  
Vol 72 (1) ◽  
Author(s):  
Léa Riera ◽  
Patrício Ramalhosa ◽  
João Canning-Clode ◽  
Ignacio Gestoso
Keyword(s):  
Benthic Communities ◽  
Oceanic Island ◽  
Indigenous Species ◽  
Non Indigenous Species

scholarly journals Responses of Southern Ocean Seafloor Habitats and Communities to Global and Local Drivers of Change

2021 ◽  
Vol 8 ◽  
Author(s):  
Madeleine J. Brasier ◽  
David Barnes ◽  
Narissa Bax ◽  
Angelika Brandt ◽  
Anne B. Christianson ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Indigenous Species ◽  
Drivers Of Change ◽  
Regional Warming ◽  
Commercial Fish ◽  
Key Species ◽  
Antarctic Shelf ◽  
Non Indigenous Species ◽  
The Antarctic ◽  
Slow Growing

Knowledge of life on the Southern Ocean seafloor has substantially grown since the beginning of this century with increasing ship-based surveys and regular monitoring sites, new technologies and greatly enhanced data sharing. However, seafloor habitats and their communities exhibit high spatial variability and heterogeneity that challenges the way in which we assess the state of the Southern Ocean benthos on larger scales. The Antarctic shelf is rich in diversity compared with deeper water areas, important for storing carbon (“blue carbon”) and provides habitat for commercial fish species. In this paper, we focus on the seafloor habitats of the Antarctic shelf, which are vulnerable to drivers of change including increasing ocean temperatures, iceberg scour, sea ice melt, ocean acidification, fishing pressures, pollution and non-indigenous species. Some of the most vulnerable areas include the West Antarctic Peninsula, which is experiencing rapid regional warming and increased iceberg-scouring, subantarctic islands and tourist destinations where human activities and environmental conditions increase the potential for the establishment of non-indigenous species and active fishing areas around South Georgia, Heard and MacDonald Islands. Vulnerable species include those in areas of regional warming with low thermal tolerance, calcifying species susceptible to increasing ocean acidity as well as slow-growing habitat-forming species that can be damaged by fishing gears e.g., sponges, bryozoan, and coral species. Management regimes can protect seafloor habitats and key species from fishing activities; some areas will need more protection than others, accounting for specific traits that make species vulnerable, slow growing and long-lived species, restricted locations with optimum physiological conditions and available food, and restricted distributions of rare species. Ecosystem-based management practices and long-term, highly protected areas may be the most effective tools in the preservation of vulnerable seafloor habitats. Here, we focus on outlining seafloor responses to drivers of change observed to date and projections for the future. We discuss the need for action to preserve seafloor habitats under climate change, fishing pressures and other anthropogenic impacts.

scholarly journals Terrestrial ecosystems of the Antarctic Peninsula and their responses to climate change and anthropogenic impacts

2020 ◽  
pp. 84-97
Author(s):  
R. Bargagli ◽  
Keyword(s):  
Antarctic Peninsula ◽  
Native Species ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Extreme Temperature ◽  
Terrestrial Ecosystems ◽  
Indigenous Species ◽  
Non Indigenous Species ◽  
Food Web Complexity ◽  
The Antarctic

Antarctica and the Southern Ocean are unique natural laboratories where organisms adapted to extreme environmental conditions have evolved in isolation for millions of years. These unique biotic communities on Earth are facing complex climatic and environmental changes. Terrestrial ecosystems in the Antarctic Peninsula Region (APR) have experienced the highest rate of climate warming and, being the most impacted by human activities, are facing the greatest risk of detrimental changes. This review provides an overview of the most recent findings on how biotic communities in terrestrial ecosystems of the Antarctic Peninsula Region (APR) are responding and will likely respond to further environmental changes and direct anthropogenic impacts. Knowledge gained from studies on relatively simple terrestrial ecosystems could be very useful in predicting what may happen in much more complex ecosystems in regions with less extreme temperature changes. The rapid warming of the APR has led to the retreat of glaciers, the loss of snow and permafrost and the increase of ice-free areas, with a consequent enhancement of soil-forming processes, biotic communities, and food web complexity. However, most human activity is concentrated in APR coastal ice-free areas and poses many threats to terrestrial ecosystems such as environmental pollution or disturbances to soilcommunities and wildlife. People who work or visit APR may inadvertently introduce alien organisms and/or spread native species to spatially isolated ice-free areas. The number of introduced non-indigenous species and xenobiotic compounds in the APR is likely to be greater than currently documented, and several biosecurity and monitoring activities are therefore suggested to Antarctic national scientific programs and tourism operators to minimize the risk of irreversible loss of integrity by the unique terrestrial ecosystems of APR.

scholarly journals Biotic effects during the settlement process of non-indigenous species in marine benthic communities

2018 ◽  
Vol 13 (2) ◽  
pp. 247-259 ◽  
Author(s):  
Ignacio Gestoso ◽  
Patrício Ramalhosa ◽  
João Canning-Clode
Keyword(s):  
Benthic Communities ◽  
Indigenous Species ◽  
Biotic Effects ◽  
Non Indigenous Species

scholarly journals Structuring effects of chemicals from the sea fanPhyllogorgia dilatataon benthic communities

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3186
Author(s):  
Felipe V. Ribeiro ◽  
Bernardo A.P. da Gama ◽  
Renato C. Pereira
Keyword(s):  
Secondary Metabolites ◽  
Benthic Communities ◽  
Allelopathic Effect ◽  
Indigenous Species ◽  
Rocky Reefs ◽  
Palythoa Caribaeorum ◽  
Physical Presence ◽  
Manipulative Experiments ◽  
Non Indigenous Species ◽  
Janeiro State

Despite advances in understanding the ecological functions of secondary metabolites from marine organisms, there has been little focus on the influence of chemically-defended species at the community level. Several compounds have been isolated from the gorgonian octocoralPhyllogorgia dilatata, a conspicuous species that forms dense canopies on rocky reefs of northern Rio de Janeiro State, Brazil. Manipulative experiments were performed to study: (1) the effects of live colonies ofP. dilatata(physical presence and chemistry) on recruitment of sympatric benthic organisms; (2) the allelopathic effects of its chemicals on competitors; and (3) chemotactic responses of the non-indigenous brittle star,Ophiothela mirabilis. Early establishment of benthic species was influenced on substrates around liveP. dilatatacolonies and some effects could be attributed to the gorgonian’s secondary metabolites.In addition, the gorgonian chemicals also exerted an allelopathic effect on the sympatric zoanthidPalythoa caribaeorum,and positive chemotaxis uponO. mirabilis. These results indicate multiple ecological roles of a chemically-defended gorgonian on settlement, sympatric competitors, and non-indigenous species.

scholarly journals La paradoxa de la biodiversitat marina antàrtica

2018 ◽  
Author(s):  
Stefano Ambroso ◽  
Josep-Maria Gili ◽  
Rebeca Zapata Guardiola ◽  
Janire Salazar
Keyword(s):  
Spatial Distribution ◽  
Benthic Communities ◽  
Benthic Organisms ◽  
Human Beings ◽  
Great Opportunity ◽  
Antarctic Continental Shelf ◽  
The World ◽  
High Level ◽  
The Antarctic ◽  
The Impact

The study of pristine places is very important for learning about the state of the oceans before the impact of human beings. Because of the extreme environmental conditions of the Antarctic continental shelf – its distance from other continents, depth, and the weight of the continental ice – it offers us a great opportunity to better understand how a pristine ecosystem would normally be. In addition to a high level of biodiversity, Antarctic benthic organisms present patterns of demographic and spatial distribution that are different from the communities of the continental platforms in other seas and oceans of the world. This makes Antarctic benthic communities look, more than one might think, like the communities with the highest known biodiversity in the world.

scholarly journals STUDY OF ECOSYSTEM OF THE SUKHUM BAY WITH EMPHASIS ANTHROPOGENIC IMPACT, ABKHAZIAN BLACK SEA COAST

2019 ◽  
Vol 22 ◽  
pp. 108-116
Author(s):  
Zhanna P. Selifonova ◽  
Pavel R. Makarevich ◽  
Ernest Z. Samyshev ◽  
Levard M. Bartsits
Keyword(s):  
Alien Species ◽  
Black Sea ◽  
Benthic Communities ◽  
Nutrient Status ◽  
Common Species ◽  
Indigenous Species ◽  
Macrophyte Community ◽  
Non Indigenous Species ◽  
Sea Area ◽  
First Time

For the first time in thirty years, baseline comprehensive studies plankton and zoobenthos of the Sukhum Bay were conducted and an assessment of its current environmental status was given. The summer phytoplankton abundance of the port of Sukhum was represented mainly by coccolithophorids  Emiliania huxleyi and diatoms algae, among the latter, the common species in polluted or eutrophic brackish waters were recorded. The presence of euglenic algae and cyanobacteria indicates a higher nutrient status, pollution and desalination of the sea area. The alien species Peridinium quinquecorne Abé (Dinophyceae) was recorded in the Abkhazian coastal waters for the first time. Totally, 7 species of tintinnids  belonging to 3 genera Favella, Tintinnopsis, Eutintinnus were established from the Sukhum Bay. Among them, the non-indigenous species Eutintinnus  tubulosus and E. apertus were noticed. Tintinnid ciliates accounted for ca. 5% of total ciliates abundance. The values of the abundance of aloricated ciliates were comparable to the values obtained  from offshore of bays and ports of the northeastern Black Sea. As the pressure of predators is reduced the well-pronounced peaks of holo- and meroplankton biomass were recorded in the last summer – early autumn. A significant part of total holoplankton biomass – 66.5 % (up to 1.1 g/m3) was composed of cladocerans  Penilia avirostris. The  meroplankton was dominated by larvae of bivalve mollusks Mytilaster lineatus,  polychaetes Polydora cornuta and cirripede barnacle Amphibalanus improvisus. The number of meroplankton in the open Sukhum port was 10–15 times lower above than a level of values obtained for ports and bays of the northeastern Black Sea. Among ichthyoplankton, the dominant species were Mullus barbatus ponticus, Diplodus annularis, Trachurus mediterraneus, Engraulis encrasicholus and Sciena umbra. Mean abundance of ichthyoplankton in vertical catches was 5–10 times lower than in offshore of Anapa and Gelendzhik of the northeastern Black Sea. And the proportion of dead eggs was 2 – 3 times higher than areas of these resort cities. The composition of macrozoobenthos was drastically depleted and resembled that of the polluted port complexes of the northeastern Black Sea. Heteromastus association  dominated in mud bottom sediments. Among spionid polychaetes, the worst invaders Streblospio gynobranchiata and Polydora cornuta have been recorded in soft bottom communities. Depletion of benthic communities, loss from the structure of the trophic web of the macrophyte community and appearance of cyanobacteria and a new alien species in the planktonic and benthic communities leads inevitably to imbalance of the structure of the Sukhum port ecosystem.

Meta-analysis on the ecological impacts of widely spread non-indigenous species in the Baltic Sea

2021 ◽  
pp. 147375
Author(s):  
Henn Ojaveer ◽  
Jonne Kotta ◽  
Okko Outinen ◽  
Heli Einberg ◽  
Anastasija Zaiko ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Meta Analysis ◽  
Ecological Impacts ◽  
Indigenous Species ◽  
The Baltic Sea ◽  
The Baltic ◽  
Non Indigenous Species

scholarly journals Glacial melt disturbance shifts community metabolism of an Antarctic seafloor ecosystem from net autotrophy to heterotrophy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ulrike Braeckman ◽  
Francesca Pasotti ◽  
Ralf Hoffmann ◽  
Susana Vázquez ◽  
Angela Wulff ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Benthic Communities ◽  
Benthic Primary Production ◽  
Community Metabolism ◽  
West Antarctic ◽  
Run Off ◽  
Net Heterotrophy ◽  
Benthic Ecosystems ◽  
The Antarctic

AbstractClimate change-induced glacial melt affects benthic ecosystems along the West Antarctic Peninsula, but current understanding of the effects on benthic primary production and respiration is limited. Here we demonstrate with a series of in situ community metabolism measurements that climate-related glacial melt disturbance shifts benthic communities from net autotrophy to heterotrophy. With little glacial melt disturbance (during cold El Niño spring 2015), clear waters enabled high benthic microalgal production, resulting in net autotrophic benthic communities. In contrast, water column turbidity caused by increased glacial melt run-off (summer 2015 and warm La Niña spring 2016) limited benthic microalgal production and turned the benthic communities net heterotrophic. Ongoing accelerations in glacial melt and run-off may steer shallow Antarctic seafloor ecosystems towards net heterotrophy, altering the metabolic balance of benthic communities and potentially impacting the carbon balance and food webs at the Antarctic seafloor.

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