Benthic communities and bioturbation history of estuarine and coastal systems: effects of hypoxia and anoxia

Modern marine plankton communities include a broad diversity of metazoans that are suspension-feeding or micropredatory as adults. Many benthic marine species have larval stages that reside, and often feed, in the plankton for brief to very long periods of time, and most marine benthic communities include large numbers of suspension-feeders. This has not always been the case. Cambrian benthic communities included relatively few suspension-feeders. Similarly, there were few metazoan clades represented in the plankton, either as adult suspension-feeders or as larvae. Review of the fossil record suggests that the diversification of the plankton and suspension-feeding marine animals began in the Late Cambrian and continued into the Ordovician. These changes were accompanied by, and probably influenced, concurrent major changes in the marine realm, including an increase in tiering within benthic communities, the replacement of the Cambrian fauna by the Paleozoic fauna, and a general taxonomic diversification. The ultimate cause of these changes is uncertain, but it appears likely that the plankton was and is a refuge from predation and bioturbation for adults and larvae alike. The expansion in plankton biomass thus provided increased ecological opportunities for suspension-feeders in the plankton and benthos.

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Annelid Fauna of the Prince Gustav Channel, a Previously Ice-Covered Seaway on the Northeastern Antarctic Peninsula

Frontiers in Marine Science ◽

10.3389/fmars.2020.595303 ◽

2021 ◽

Vol 7 ◽

Author(s):

Regan Drennan ◽

Thomas G. Dahlgren ◽

Katrin Linse ◽

Adrian G. Glover

Keyword(s):

Antarctic Peninsula ◽

Demographic History ◽

Benthic Communities ◽

Weddell Sea ◽

Ice Shelf ◽

Camera System ◽

Evolutionary Origins ◽

History Of ◽

Dynamic Habitat ◽

Underwater Camera

The Prince Gustav Channel is a narrow seaway located in the western Weddell Sea on the northeastern-most tip of the Antarctic Peninsula. The channel is notable for both its deep (>1200 m) basins, and a dynamic glacial history that most recently includes the break-up of the Prince Gustav Ice Shelf, which covered the southern portion of the channel until its collapse in 1995. However, the channel remains mostly unsampled, with very little known about its benthic biology. We present a preliminary account of the benthic annelid fauna of the Prince Gustav Channel in addition to samples from Duse Bay, a sheltered, glacier-influenced embayment in the northwestern portion of the channel. Samples were collected using an Agassiz Trawl, targeting megafaunal and large macrofaunal sized animals at depths ranging between 200–1200 m; the seafloor and associated fauna were also documented in situ using a Shallow Underwater Camera System (SUCS). Sample sites varied in terms of depth, substrate type, and current regime, and communities were locally variable across sites in terms of richness, abundance, and both taxonomic and functional composition. The most diverse family included the motile predator/scavenger Polynoidae, with 105 individuals in at least 12 morphospecies, primarily from a single site. This study provides first insights into diverse and spatially heterogeneous benthic communities in a dynamic habitat with continuing glacial influence, filling sampling gaps in a poorly studied region of the Southern Ocean at direct risk from climate change. These specimens will also be utilized in future molecular investigations, both in terms of describing the genetic biodiversity of this site and as part of wider phylogeographic and population genetic analyses assessing the connectivity, evolutionary origins, and demographic history of annelid fauna in the region.

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A review of the diatom research in the Gulf of Gdańsk and Vistula Lagoon (southern Baltic Sea)

Oceanological and Hydrobiological Studies ◽

10.2478/s13545-013-0091-x ◽

2013 ◽

Vol 42 (3) ◽

Cited By ~ 2

Author(s):

Małgorzata Witak

Keyword(s):

Surface Sediments ◽

Benthic Communities ◽

Late Glacial ◽

Vistula Lagoon ◽

Gulf Of Gdańsk ◽

History Of ◽

Gulf Of Gdansk ◽

Late Glacial And Holocene ◽

Different Parts ◽

The Vistula Lagoon

AbstractThe paper presents the history of diatom studies carried out in the Gulf of Gdańsk and the Vistula Lagoon since the beginning of the 20th century. One aspect of the research focuses on describing the structure of planktonic and benthic communities living in different parts of the area or occurring in their surface sediments as taphocoenoses. Other investigations concentrate on the fossil diatom flora, which is widely used in the research on the Late Glacial and Holocene to resolve paleogeographic, sedimentological and paleoecological problems.

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The study of crinoids during the 20th century and the challenges of the 21st century

Journal of Paleontology ◽

10.1017/s0022336000017212 ◽

2001 ◽

Vol 75 (6) ◽

pp. 1161-1173 ◽

Cited By ~ 6

Author(s):

William I. Ausich ◽

Thomas W. Kammer

Keyword(s):

20Th Century ◽

21St Century ◽

Benthic Communities ◽

Primary Objective ◽

Systematic Revision ◽

Early 21St Century ◽

Phylogenetic Classification ◽

The Third ◽

History Of ◽

Comprehensive Classification

Development of a phylogenetic classification has been a primary pursuit of crinoid paleontologists during the 20th century. Wachsmuth and Springer and Bather vigorously debated crinoid classification during the waning years of the 19th century, and although tremendous progress has been made a comprehensive phylogenetic classification is still the primary objective for crinoid research during the early 21st century. Twentieth century crinoid studies are divisible into four periods. The direct influence of Frank Springer and Francis Bather continued until approximately 1925. Descriptive studies dominated the period of 1926–1943 and culminated in a comprehensive classification of Paleozoic crinoids that was a combination of the ideas of Wachsmuth and Springer and Bather. The end of the third period, 1944–1978, was marked by publication of theTreatise on Invertebrate Paleontology. TheTreatisecompilation brought together classification ideas for the entire class into a truly comprehensive classification, although problems remained with the phylogenetic underpinnings of theTreatiseclassification. During the third period, pioneering work on crinoid paleobiology laid the foundation for significant paleobiology advances for the fourth, 1979–1999, period. This last period also witnessed significant advances in the taxonomy of crinoid faunas at critical intervals, the taxonomy of crinoids from new geographic areas, and working toward the solution to the origin and early evolution of the Crinoidea.Continued work on crinoids in the 21st century promises to provide significant advances both for understanding the evolutionary history of crinoids and for understanding the history of epifaunal benthic communities through time. Immediate challenges include completion of a comprehensive phylogenetic classification, which will open the door for evolutionary paleoecologic and paleobiology studies; utilization of computerized morphometric techniques in the analysis of functional morphology; systematic studies of new faunas in critical intervals; discovery of faunas in new geographic areas to better constrain knowledge of crinoid biogeography; and modern systematic revision of classic North American and European faunas.

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Sponge contribution to the silicon cycle of a diatom-rich shallow bay

10.1101/2021.10.20.465147 ◽

2021 ◽

Author(s):

Maria Lopez-Acosta ◽

Manuel Maldonado ◽

Jacques Grall ◽

Axel Ehrhold ◽

Celia Sitja ◽

...

Keyword(s):

Benthic Communities ◽

Standing Stock ◽

Siliceous Sponge ◽

Planktonic Diatoms ◽

Silicon Cycle ◽

Coastal Systems ◽

Superficial Sediments ◽

Bay Of Brest ◽

Dissolved Silicon ◽

Shallow Bay

In coastal systems, planktonic and benthic silicifiers compete for the pool of dissolved silicon, a nutrient required to make their skeletons. The contribution of planktonic diatoms to the cycling of silicon in coastal systems is often well characterized, while that of benthic silicifiers such as sponges has rarely been quantified. Herein, silicon fluxes and stocks are quantified for the sponge fauna in the benthic communities of the Bay of Brest (France). A total of 45 siliceous sponge species living in the Bay account for a silicon standing stock of 1215 tons, while that of diatoms is only 27 tons. The silicon reservoir accumulated as sponge skeletons in the superficial sediments of the Bay rises to 1775 tons, while that of diatom skeletons is only 248 tons. These comparatively large stocks of sponge silicon were estimated to cycle two orders of magnitude slower than the diatom stocks. Sponge silicon stocks need years to decades to be renewed, while diatom turnover lasts only days. Although the sponge monitoring over the last 6 years indicates no major changes of the sponge stocks, our results do not allow to conclude if the silicon sponge budget of the Bay is at steady state, and potential scenarios are discussed. The findings buttress the idea that sponges and diatoms play contrasting roles in the marine silicon cycle. The budgets of these silicon major users need to be integrated and their connections revealed, if we aim to reach a full understanding of the silicon cycling in coastal ecosystems.

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