Large-scale marine ecosystem change and the conservation of marine mammals

AbstractTropical Pacific upwelling-dependent ecosystems are the most productive and variable worldwide, mainly due to the influence of El Niño Southern Oscillation (ENSO). ENSO can be forecasted seasons ahead thanks to assorted climate precursors (local-Pacific processes, pantropical interactions). However, owing to observational data scarcity and bias-related issues in earth system models, little is known about the importance of these precursors for marine ecosystem prediction. With recently released reanalysis-nudged global marine ecosystem simulations, these constraints can be sidestepped, allowing full examination of tropical Pacific ecosystem predictability. By complementing historical fishing records with marine ecosystem model data, we show herein that equatorial Atlantic Sea Surface Temperatures (SSTs) constitute a superlative predictability source for tropical Pacific marine yields, which can be forecasted over large-scale areas up to 2 years in advance. A detailed physical-biological mechanism is proposed whereby Atlantic SSTs modulate upwelling of nutrient-rich waters in the tropical Pacific, leading to a bottom-up propagation of the climate-related signal across the marine food web. Our results represent historical and near-future climate conditions and provide a useful springboard for implementing a marine ecosystem prediction system in the tropical Pacific.

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The impact of the Messinian Salinity Crisis on marine biota

10.5194/egusphere-egu2020-5799 ◽

2020 ◽

Author(s):

Konstantina Agiadi ◽

Niklas Hohmann ◽

Giorgio Carnevale ◽

Elsa Gliozzi ◽

Constanza Faranda ◽

...

Keyword(s):

Marine Mammals ◽

Planktonic Foraminifera ◽

Marine Ecosystem ◽

Functional Change ◽

Marine Biota ◽

Messinian Salinity Crisis ◽

Marine Fauna ◽

Independent Evidence ◽

The Mediterranean ◽

The Impact

<p>The Messinian Salinity Crisis (MSC) was the greatest paleoenvironmental perturbation the Mediterranean has ever seen. The literature is abundant in hypotheses on the repercussions of the MSC on organisms. However, all these are based on incomplete and still uncertain scenarios about the MSC evolution, as well as on the assumption that such a paleoenvironmental perturbation must have completely reset marine biota. Having prevailed for many decades now, this assumption has leaked from paleontology and geosciences to biological sciences, with numerous studies taking this scenario for granted instead of using it as a starting hypothesis to be tested. Here, we review and revise the marine fossil record across the Mediterranean from the Tortonian until the Zanclean to follow the current rules of nomenclature, correct misidentifications, and control for stratigraphic misplacements. We examine the composition of marine faunas, both taxonomically and considering the function of each group in the marine ecosystem and the transfer of energy through the marine food web. Specifically, we investigate the following functional groups: 1) primary producers, 2) secondary producers, 3) primary consumers, 4) secondary consumers, and 5) top predators. Our study includes sea grasses, phytoplankton, corals, benthic and planktonic foraminifera, bivalves, gastropods, brachiopods, echinoids, bryozoans, fishes, ostracods, and marine mammals. We calculate biodiversity indexes to provide independent evidence quantifying to what degree the marine fauna underwent:</p><ol><li>A drop of overall regional biodiversity of the Mediterranean due to environmental stress during the Messinian.</li> <li>A taxonomic and functional change between the Tortonian, Messinian, and the Zanclean, that is before and after the MSC, as well as during the precursor events to that actual crisis taking place after the Tortonian/Messinian boundary.</li> <li>The onset of the present-day west-to-east decreasing gradient in species richness, which has been related to the sea temperature and productivity gradients and the distance from the Gibraltar connection to the Atlantic.</li> </ol>

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Marine Ecosystem Assessment for the Southern Ocean: Birds and Marine Mammals in a Changing Climate

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2020.566936 ◽

2020 ◽

Vol 8 ◽

Author(s):

Sophie Bestley ◽

Yan Ropert-Coudert ◽

Susan Bengtson Nash ◽

Cassandra M. Brooks ◽

Cédric Cotté ◽

...

Keyword(s):

Southern Ocean ◽

Marine Mammals ◽

Marine Ecosystem ◽

Ecosystem Assessment ◽

Changing Climate

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Community Replacement Pathways: What Do Fossil Sequences Reveal About Marine Ecosystem Transitions?

The Paleontological Society Special Publications ◽

10.1017/s2475262200005530 ◽

1990 ◽

Vol 5 ◽

pp. 262-272

Author(s):

William Miller

Keyword(s):

Fossil Record ◽

Large Scale ◽

Marine Ecosystem ◽

Small Scale ◽

Data Sets ◽

Mass Extinctions ◽

Ultimate Cause ◽

Long Time ◽

History Of ◽

Time And Energy

Paleontologists have lavished much time and energy on description and explanation of large-scale patterns in the fossil record (e.g., mass extinctions, histories of monophyletic taxa, deployment of major biogeographic units), while paying comparatively little attention to biologic patterns preserved only in local stratigraphic sequences. Interpretation of the large-scale patterns will always be seen as the chief justification for the science of paleontology, but solving problems framed by long time spans and large areas is rife with tenuous inference and patterns are prone to varied interpretation by different investigators using virtually the same data sets (as in the controversy over ultimate cause of the terminal Cretaceous extinctions). In other words, the large-scale patterns in the history of life are the true philosophical property of paleontology, but there will always be serious problems in attempting to resolve processes that transpired over millions to hundreds-of-millions of years and encompassed vast areas of seafloor or landscape. By contrast, less spectacular and more commonplace changes in local habitats (often related to larger-scale events and cycles) and attendant biologic responses are closer to our direct experience of the living world and should be easier to interpret unequivocally. These small-scale responses are reflected in the fossil record at the scale of local outcrops.

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First Report on the Prevalence and Subtype Distribution of Blastocystis sp. in Edible Marine Fish and Marine Mammals: A Large Scale-Study Conducted in Atlantic Northeast and on the Coasts of Northern France

Microorganisms ◽

10.3390/microorganisms8030460 ◽

2020 ◽

Vol 8 (3) ◽

pp. 460 ◽

Cited By ~ 3

Author(s):

Nausicaa Gantois ◽

Angélique Lamot ◽

Yuwalee Seesao ◽

Colette Creusy ◽

Luen-Luen Li ◽

...

Keyword(s):

Genetic Diversity ◽

Marine Fish ◽

Marine Mammals ◽

Large Scale ◽

Zoonotic Transmission ◽

Northern France ◽

Natural Hosts ◽

Blastocystis Sp ◽

Large Scale Survey ◽

Polymerase Chain

Blastocystis is frequently identified in humans and animal hosts and exhibits a large genetic diversity with the identification of 17 subtypes (STs). Despite its zoonotic potential, its prevalence and ST distribution in edible marine fish and marine mammals remain unknown. A large-scale survey was thus conducted by screening 345 fish caught in Atlantic Northeast and 29 marine mammals stranded on the coasts of northern France for the presence of the parasite using real-time Polymerase Chain Reaction PCR. The prevalence of the parasite was about 3.5% in marine fish. These animals were mostly colonized by poikilotherm-derived isolates not identified in humans and corresponding to potential new STs, indicating that fish are natural hosts of Blastocystis. Marine fishes are also carriers of human STs and represent a likely limited source of zoonotic transmission. 13.8% of the marine mammals tested were colonized and 6 different STs were identified including 3 potential new STs. The risk of zoonotic transmission through marine mammals is insignificant due to the lack of repeated contact with humans. The present survey represents the first data regarding the prevalence and ST distribution of Blastocystis in marine fish and marine mammals and provides new insights into its genetic diversity, host range and transmission.

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From sea ice to seals: a moored marine ecosystem observatory in the Arctic

Ocean Science ◽

10.5194/os-14-1423-2018 ◽

2018 ◽

Vol 14 (6) ◽

pp. 1423-1433 ◽

Cited By ~ 5

Author(s):

Claudine Hauri ◽

Seth Danielson ◽

Andrew M. P. McDonnell ◽

Russell R. Hopcroft ◽

Peter Winsor ◽

...

Keyword(s):

Sea Ice ◽

Marine Mammals ◽

Chukchi Sea ◽

Marine Ecosystem ◽

Extreme Environment ◽

The Arctic ◽

Zooplankton Abundance ◽

Test Bed ◽

Ecosystem Monitoring ◽

Cold Temperatures

Abstract. Although Arctic marine ecosystems are changing rapidly, year-round monitoring is currently very limited and presents multiple challenges unique to this region. The Chukchi Ecosystem Observatory (CEO) described here uses new sensor technologies to meet needs for continuous, high-resolution, and year-round observations across all levels of the ecosystem in the biologically productive and seasonally ice-covered Chukchi Sea off the northwest coast of Alaska. This mooring array records a broad suite of variables that facilitate observations, yielding better understanding of physical, chemical, and biological couplings, phenologies, and the overall state of this Arctic shelf marine ecosystem. While cold temperatures and 8 months of sea ice cover present challenging conditions for the operation of the CEO, this extreme environment also serves as a rigorous test bed for innovative ecosystem monitoring strategies. Here, we present data from the 2015–2016 CEO deployments that provide new perspectives on the seasonal evolution of sea ice, water column structure, and physical properties, annual cycles in nitrate, dissolved oxygen, phytoplankton blooms, and export, zooplankton abundance and vertical migration, the occurrence of Arctic cod, and vocalizations of marine mammals such as bearded seals. These integrated ecosystem observations are being combined with ship-based observations and modeling to produce a time series that documents biological community responses to changing seasonal sea ice and water temperatures while establishing a scientific basis for ecosystem management.

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Population Dynamics of the ‘Golden Tides’ Seaweed, Sargassum horneri, on the Southwestern Coast of Korea: The Extent and Formation of Golden Tides

Sustainability ◽

10.3390/su12072903 ◽

2020 ◽

Vol 12 (7) ◽

pp. 2903 ◽

Cited By ~ 1

Author(s):

Sun Kyeong Choi ◽

Hyun-Ju Oh ◽

Suk-Hyun Yun ◽

Hyuk Je Lee ◽

Kyounghoon Lee ◽

...

Keyword(s):

Population Dynamics ◽

Large Scale ◽

Marine Ecosystem ◽

Life Cycles ◽

Sargassum Horneri ◽

Gene Markers ◽

Average Biomass ◽

Environmental Difference ◽

Few Data ◽

Specific Growth Rates

Since 2015, troublesome masses of floating Sargassum horneri have been introduced via ocean currents and winds to the southwestern coastline of Korea, including Jeju Island. These massive mats have caused considerable damage to the aquaculture industry, tourism, and the marine ecosystem. Most previous studies of S. horneri have focused on cultivation, the development of gene markers, and photosynthetic activity, but few data on population dynamics are available. We investigated the population dynamics of native S. horneri off the southwestern coast of Korea with the aim of predicting the formation of golden tides. Populations at two sites had obligate annual life cycles. Thalli were recruited during the period September–November, grew during the period December–April, and senesced by July. This pattern reflected seasonal trends in water temperature. Specific growth rates and heights of the thalli at Munseom were significantly higher than those at Jindo. The greatest environmental difference between the two sites is probably the degree of exposure to wave action. Mortality density (thalli lost per unit area) in the Munseom population was highest during the period December–January (i.e., 2–3 months after recruitment) and in March. Most thalli in the Jindo population died off in July when water temperatures increased. The maximum average biomass of S. horneri thalli detaching from the substrata reached 1.6 kg fresh weight m–2 during January and March. Thus, large-scale drifting mats were formed by S. horneri detachment from the substrata. Despite the differences in space and environment between China and Korea, our findings will enable quantitative assessments of the overall floating Sargassum biomass in the East China and Yellow Seas.

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Integrated Genomic and Metabolomic Approach to the Discovery of Potential Anti-Quorum Sensing Natural Products from Microbes Associated with Marine Samples from Singapore

Marine Drugs ◽

10.3390/md17010072 ◽

2019 ◽

Vol 17 (1) ◽

pp. 72 ◽

Cited By ~ 8

Author(s):

Ji Ong ◽

Hui Goh ◽

Swee Lim ◽

Li Pang ◽

Joyce Chin ◽

...

Keyword(s):

Drug Discovery ◽

Quorum Sensing ◽

Large Scale ◽

Marine Ecosystem ◽

Gene Clusters ◽

Integrated Approach ◽

Rrna Gene ◽

Dependent Manner ◽

Bacterial Strains ◽

Reporter System

With 70% of the Earth’s surface covered in water, the marine ecosystem offers immense opportunities for drug discovery and development. Due to the decreasing rate of novel natural product discovery from terrestrial sources in recent years, many researchers are beginning to look seaward for breakthroughs in new therapeutic agents. As part of an ongoing marine drug discovery programme in Singapore, an integrated approach of combining metabolomic and genomic techniques were initiated for uncovering novel anti-quorum sensing molecules from bacteria associated with subtidal samples collected in the Singapore Strait. Based on the culture-dependent method, a total of 102 marine bacteria strains were isolated and the identities of selected strains were established based on their 16S rRNA gene sequences. About 5% of the marine bacterial organic extracts showed quorum sensing inhibitory (QSI) activity in a dose-dependent manner based on the Pseudomonas aeruginosa QS reporter system. In addition, the extracts were subjected to mass spectrometry-based molecular networking and the genome of selected strains were analysed for known as well as new biosynthetic gene clusters. This study revealed that using integrated techniques, coupled with biological assays, can provide an effective and rapid prioritization of marine bacterial strains for downstream large-scale culturing for the purpose of isolation and structural elucidation of novel bioactive compounds.

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Dynamical connections between large marine ecosystems of austral South America based on numerical simulations

Ocean Science ◽

10.5194/os-16-271-2020 ◽

2020 ◽

Vol 16 (2) ◽

pp. 271-290 ◽

Cited By ~ 2

Author(s):

Karen Guihou ◽

Alberto R. Piola ◽

Elbio D. Palma ◽

Maria Paz Chidichimo

Keyword(s):

South America ◽

Interannual Variability ◽

Large Scale ◽

Marine Ecosystem ◽

Outer Part ◽

Marine Ecosystems ◽

Seasonal And Interannual Variability ◽

Magellan Strait ◽

The Pacific ◽

Large Marine Ecosystem

Abstract. The Humboldt Large Marine Ecosystem (HLME) and Patagonian Large Marine Ecosystem (PLME) are the two largest marine ecosystems in the Southern Hemisphere and are respectively located along the Pacific and Atlantic coasts of southern South America. This work investigates the exchange between these two LMEs and its seasonal and interannual variability by employing numerical model results and offline particle-tracking algorithms. Our analysis suggests a general poleward transport on the southern region of the HLME, a well-defined flux from the Pacific to the Atlantic, and equatorward transport on the PLME. Lagrangian simulations show that the majority of the southern PS waters originate from the upper layer in the southeast South Pacific (<200 m), mainly from the southern Chile and Cape Horn shelves. The exchange takes place through the Le Maire Strait, Magellan Strait, and the shelf break. These inflows amount to a net northeastward transport of 0.88 Sv at 51∘ S in the southern PLME. The transport across the Magellan Strait is small (0.1 Sv), but due to its relatively low salinity it greatly impacts the density and surface circulation of the coastal waters of the southern PLME. The water masses flowing into the Malvinas Embayment eventually reach the PLME through the Malvinas Shelf and occupy the outer part of the shelf. The seasonal and interannual variability of the transport are also addressed. On the southern PLME, the interannual variability of the shelf exchange is partly explained by the large-scale wind variability, which in turn is partly associated with the Southern Annular Mode (SAM) index (r=0.52).

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