Challenges of deep-sea biodiversity assessments in the Southern Ocean

Despite recent progress in deep-sea biodiversity assessments in the Southern Ocean (SO), there remain gaps in our knowledge that hamper effi cient deep-sea monitoring in times of rapid climate change. These include geographical sampling bias, depth and size-dependent faunal gaps in biology, ecology, distribution, and phylogeography, and the evolution of SO species. The phenomena of species patchiness and rarity are still not well understood, possibly because of our limited understanding of physiological adaptations and thresholds. Even though some shallow water species have been investigated physiologically, community scale studies on the effects of multiple stressors related to ongoing environmental change, including temperature rise, ocean acidification, and shifts in deposition of phytoplankton, are completely unknown for deep-sea organisms. Thus, the establishment of long-term and coordinated monitoring programs, such as those rapidly growing under the umbrella of the Southern Ocean Observing System (SOOS) or the Deep Ocean Observing Strategy (DOOS), may represent unique tools for measuring the status and trends of deep-sea and SO ecosystem

Analysis of Energy Flow in US GLOBEC Ecosystems Using End-to-End Models

End-to-end models were constructed to examine and compare the trophic structure and energy flow in coastal shelf ecosystems of four US Global Ocean Ecosystem Dynamics (GLOBEC) study regions: the Northern California Current, the Central Gulf of Alaska, Georges Bank, and the Southwestern Antarctic Peninsula. High-quality data collected on system components and processes over the life of the program were used as input to the models. Although the US GLOBEC program was species-centric, focused on the study of a selected set of target species of ecological or economic importance, we took a broader community-level approach to describe end-to-end energy flow, from nutrient input to fishery production. We built four end-to-end models that were structured similarly in terms of functional group composition and time scale. The models were used to identify the mid-trophic level groups that place the greatest demand on lower trophic level production while providing the greatest support to higher trophic level production. In general, euphausiids and planktivorous forage fishes were the critical energy-transfer nodes; however, some differences between ecosystems are apparent. For example, squid provide an important alternative energy pathway to forage fish, moderating the effects of changes to forage fish abundance in scenario analyses in the Central Gulf of Alaska. In the Northern California Current, large scyphozoan jellyfish are important consumers of plankton production, but can divert energy from the rest of the food web when abundant

From rivers to marine environments: A constantly evolving microbial community within the plastisphere

Plastics accumulate in the environment and the Mediterranean Sea is one of the most polluted sea in the world. The plastic surface is rapidly colonized by microorganisms, forming the plastisphere. Our unique sampling supplied 107 plastic pieces from 22 geographical sites from four aquatic ecosystems (river, estuary, harbor and inshore) in the south of France in order to better understand the parameters which influence biofilm composition. In parallel, 48 enrichment cultures were performed to investigate the presence of plastic degrading-bacteria in the plastisphere. In this context, we showed that the most important drivers of microbial community structure were the sampling site followed by the polymer chemical composition. The study of pathogenic genus distribution highlighted that only 11% of our plastic samples contained higher proportions of Vibrio compared to the natural environment. Finally, results of the enrichment cultures showed a selection of hydrocarbon-degrading microorganisms suggesting their potential role in the plastic degradation

Dividing up the pie: Whales, fish, and humans as competitors

Similarly structured food web models of four coastal ecosystems (Northern California Current, Central Gulf of Alaska, Georges Bank, southwestern Antarctic Peninsula) were used to investigate competition among whales, fishes, pinnipeds, and humans. Two analysis strategies simulated the effects of historic baleen and odontocete whale abundances across all trophic levels: food web structure scenarios and time-dynamic scenarios. Direct competition between whales and commercial fisheries is small at current whale abundances; whales and fisheries each take similar proportions of annual pelagic fish production (4-7%). Scenarios show that as whale populations grow, indirect competition between whales and fish for zooplankton would more likely impact fishery production than would direct competition for fish between whales and commercial fisheries. Increased baleen whale abundance would have greater and broader indirect effects on upper trophic levels and fisheries than a similar increase in odontocete abundance. Time-dynamic scenarios, which allow for the evolution of compensatory mechanisms, showed more modest impacts than structural scenarios, which show the immediate impacts of altered energy pathways. Structural scenarios show that in terms of energy availability, there is potential for large increases in whale abundance without major changes to existing food web structures and without substantial reduction of fishery production. For each ecosystem, a five-fold increase in baleen whale abundance could be supported with minor disruptions to existing energy flow pathways. However, such an increase would remain below historical population levels for many cetaceans. A larger expansion (20X) could be accommodated only with large reductions in energy flow to competitor groups. The scope for odontocete expansion varies between ecosystems but may be more restricted than the scope for baleen expansion because they feed at higher, less productive trophic levels. (C) 2013 Elsevier Ltd. All rights reserved.Keywords: Krill, Fisheries, Variability, Abundance, Antarctica, Ecosystem, Baleen whales, Ecopath, Population, Southern ocea

Developing Priority Variables (“ecosystem Essential Ocean Variables” — eEOVs) for Observing Dynamics and Change in Southern Ocean Ecosystems

Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect at appropriate spatial and temporal scales and are useful to the extent that they contribute to direct estimation of trends and/or attribution, and/or development of ecological (statistical or simulation) models to support assessments. In this paper we outline the rationale, including establishing a set of criteria, for selecting eEOVs for the SOOS and develop a list of candidate eEOVs for further evaluation. Other than habitat variables, nine types of eEOVs for Southern Ocean taxa are identified within three classes: state (magnitude, genetic/species, size spectrum), predator–prey (diet, foraging range), and autecology (phenology, reproductive rate, individual growth rate, detritus). Most candidates for the suite of Southern Ocean taxa relate to state or diet. Candidate autecological eEOVs have not been developed other than for marine mammals and birds. We consider some of the spatial and temporal issues that will influence the adoption and use of eEOVs in an observing system in the Southern Ocean, noting that existing operations and platforms potentially provide coverage of the four main sectors of the region — the East and West Pacific, Atlantic and Indian. Lastly, we discuss the importance of simulation modelling in helping with the design of the observing system in the long term. Regional boundary: south of 30°S

Analysis of Energy Flow in US GLOBEC Ecosystems Using End-to-End Models

End-to-end models were constructed to examine and compare the trophic structure and energy flow in coastal shelf ecosystems of four US Global Ocean Ecosystem Dynamics (GLOBEC) study regions: the Northern California Current, the Central Gulf of Alaska, Georges Bank, and the Southwestern Antarctic Peninsula. High-quality data collected on system components and processes over the life of the program were used as input to the models. Although the US GLOBEC program was species-centric, focused on the study of a selected set of target species of ecological or economic importance, we took a broader community-level approach to describe end-to-end energy flow, from nutrient input to fishery production. We built four end-to-end models that were structured similarly in terms of functional group composition and time scale. The models were used to identify the mid-trophic level groups that place the greatest demand on lower trophic level production while providing the greatest support to higher trophic level production. In general, euphausiids and planktivorous forage fishes were the critical energy-transfer nodes; however, some differences between ecosystems are apparent. For example, squid provide an important alternative energy pathway to forage fish, moderating the effects of changes to forage fish abundance in scenario analyses in the Central Gulf of Alaska. In the Northern California Current, large scyphozoan jellyfish are important consumers of plankton production, but can divert energy from the rest of the food web when abundant

Developing priority variables ("ecosystem Essential Ocean Variables" — eEOVs) for observing dynamics and change in Southern Ocean ecosystems

Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect at appropriate spatial and temporal scales and are useful to the extent that they contribute to direct estimation of trends and/or attribution, and/or development of ecological (statistical or simulation) models to support assessments. In this paper we outline the rationale, including establishing a set of criteria, for selecting eEOVs for the SOOS and develop a list of candidate eEOVs for further evaluation. Other than habitat variables, nine types of eEOVs for Southern Ocean taxa are identified within three classes: state (magnitude, genetic/species, size spectrum), predator–prey (diet, foraging range), and autecology (phenology, reproductive rate, individual growth rate, detritus). Most candidates for the suite of Southern Ocean taxa relate to state or diet. Candidate autecological eEOVs have not been developed other than for marine mammals and birds. We consider some of the spatial and temporal issues that will influence the adoption and use of eEOVs in an observing system in the Southern Ocean, noting that existing operations and platforms potentially provide coverage of the four main sectors of the region — the East and West Pacific, Atlantic and Indian. Lastly, we discuss the importance of simulation modelling in helping with the design of the observing system in the long term. Regional boundary: south of 30°S

ClimateFish: A Collaborative Database to Track the Abundance of Selected Coastal Fish Species as Candidate Indicators of Climate Change in the Mediterranean Sea

Under the effects of global warming, many animals and plants are undergoing rapid distribution shifts. These changes can be particularly rapid in marine fishes, and many species have responded markedly to recent increases in sea temperature. ClimateFish is an open-access database, which collates abundance data for 7 Mediterranean indigenous and 8 non-indigenous fishes, proposed as candidate indicators of climate change. These species have been selected by a network of Mediterranean scientists based on their wide distribution, responsiveness to temperature conditions and easy identification. Data are periodically collected according to a standard visual census protocol in four different depth layers. At present, the database collates data on a total number of 101'771 observed individuals belonging to the 15 target species. Counts were realized along 3142 transects carried out in 7 Mediterranean countries between 2009 and 2021. This database, associated with climate data, offers new opportunities to investigate spatiotemporal effects of climate change and to test the effectiveness of each selected indicator. Data are available at https://doi.org/10.17882/86784.The Mediterranean ClimateFish initiative was initially conceived by the international basin wide monitoring program CIESM Tropical Signals (funded by the Albert II of Monaco Foundation) and subsequently supported by the Interreg Med Programme (Projects: MPA-ADAPT, grant number 1MED15_3.2_M2_337 and MPA Engage, grant number 5MED18_3.2_M23_007), 85% co funded by the European Regional Development Fund

The mediterranean sea we want

open58siThis paper presents major gaps and challenges for implementing the UN Decade of Ocean Science for Sustainable Development (2021-2030) in the Mediterranean region. The authors make recommendations on the scientific knowledge needs and co-design actions identified during two consultations, part of the Decade preparatory-phase, framing them in the Mediterranean Sea’s unique environmental and socio-economic perspectives. According to the ‘Mediterranean State of the Environment and Development Report 2020’ by the United Nations Environment Programme Mediterranean Action Plan and despite notable progress, the Mediterranean region is not on track to achieve and fully implement the Sustainable Development Goals of Agenda 2030. Key factors are the cumulative effect of multiple human-induced pressures that threaten the ecosystem resources and services in the global change scenario. The basin, identified as a climate change vulnerability hotspot, is exposed to pollution and rising impacts of climate change. This affects mainly the coastal zones, at increasing risk of extreme events and their negative effects of unsustainable management of key economic assets. Transitioning to a sustainable blue economy is the key for the marine environment’s health and the nourishment of future generations. This challenging context, offering the opportunity of enhancing the knowledge to define science-based measures as well as narrowing the gaps between the Northen and Southern shores, calls for a joint (re)action. The paper reviews the state of the art of Mediterranean Sea science knowledge, sets of trends, capacity development needs, specific challenges, and recommendations for each Decade’s societal outcome. In the conclusions, the proposal for a Mediterranean regional programme in the framework of the Ocean Decade is addressed. The core objective relies on integrating and improving the existing ocean-knowledge, Ocean Literacy, and ocean observing capacities building on international cooperation to reach the “Mediterranean Sea that we want”.openCappelletto M.; Santoleri R.; Evangelista L.; Galgani F.; Garces E.; Giorgetti A.; Fava F.; Herut B.; Hilmi K.; Kholeif S.; Lorito S.; Sammari C.; Lianos M.C.; Celussi M.; D'alelio D.; Francocci F.; Giorgi G.; Canu D.M.; Organelli E.; Pomaro A.; Sannino G.; Segou M.; Simoncelli S.; Babeyko A.; Barbanti A.; Chang-Seng D.; Cardin V.; Casotti R.; Drago A.; Asmi S.E.; Eparkhina D.; Fichaut M.; Hema T.; Procaccini G.; Santoro F.; Scoullos M.; Solidoro C.; Trincardi F.; Tunesi L.; Umgiesser G.; Zingone A.; Ballerini T.; Chaffai A.; Coppini G.; Gruber S.; Knezevic J.; Leone G.; Penca J.; Pinardi N.; Petihakis G.; Rio M.-H.; Said M.; Siokouros Z.; Srour A.; Snoussi M.; Tintore J.; Vassilopoulou V.; Zavatarelli M.Cappelletto M.; Santoleri R.; Evangelista L.; Galgani F.; Garces E.; Giorgetti A.; Fava F.; Herut B.; Hilmi K.; Kholeif S.; Lorito S.; Sammari C.; Lianos M.C.; Celussi M.; D'alelio D.; Francocci F.; Giorgi G.; Canu D.M.; Organelli E.; Pomaro A.; Sannino G.; Segou M.; Simoncelli S.; Babeyko A.; Barbanti A.; Chang-Seng D.; Cardin V.; Casotti R.; Drago A.; Asmi S.E.; Eparkhina D.; Fichaut M.; Hema T.; Procaccini G.; Santoro F.; Scoullos M.; Solidoro C.; Trincardi F.; Tunesi L.; Umgiesser G.; Zingone A.; Ballerini T.; Chaffai A.; Coppini G.; Gruber S.; Knezevic J.; Leone G.; Penca J.; Pinardi N.; Petihakis G.; Rio M.-H.; Said M.; Siokouros Z.; Srour A.; Snoussi M.; Tintore J.; Vassilopoulou V.; Zavatarelli M

A web of interests, diplomacy and science in the Southern Ocean

International audiencePrior to the inception of the Antarctic Treaty (AT), marine mammals and fish stocks were commercially overexploited in the Southern Ocean (SO) without regard for the consequences for individual species and for the ecosystems. The AT resulted in the development of bodies with an interest in ecosystem-based management, which in turn stimulated a large number of marine ecology studies. These studies, largely undertaken under the umbrella of the Committee for Environmental Protection (CEP) and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), have been ongoing for 30 years and resulted in the development of a wealth of scientific knowledge on SO marine ecology. Despite the knowledge acquired, effective protection measures for SO marine ecosystems are still lacking and recent development of a Ross Sea Antarctic toothfish fishery has the potential to alter ecosystem structure and function of regions of the SO until today relatively untouched by human activities. The Antarctic toothfish is a top predator with slow growth rates and delayed maturity. Removals of corresponding species in other marine ecosystems altered the equilibrium of the food webs, determined trophic cascades, and reduced the value of the ecosystem services. Concern for the expansion of the Antarctic toothfish fishery has been expressed by the SO scientific community and by Non-Governmental Organizations (NGOs). Despite the importance of these issues, the general public and the non-specialized scientific community seem not understand that even with the high level of environmental protection assured to the Antarctic continent through the AT the threats to SO ecosystems still remain. A way to ensure protection of SO ecosystems is through development of a network of representative marine protected areas (MPAs) where fishing activities are strictly regulated or excluded. More than 500 Antarctic and non-Antarctic scientists supported designation of a MPA for the whole Ross Sea and 15 environmental NGOs started a worldwide campaign in support of establishment of a network of SO MPAs. CCAMLR and the AT have agreed to work toward the development of a network of SO MPAs by 2012. They have the support of the scientific community in this and it is important that action occurs rapidly to mitigate the effects of expanding fisheries. This is an opportunity to develop for SO marine ecosystems the same level of protection as that provided for the Antarctic continent