CHALLENGE 2: Protect and restore ecosystems and biodiversity:

Understand the effects of multiple stressors on ocean ecosystems, and develop solutions to monitor, protect, manage and restore ecosystems and their biodiversity under changing environmental, social and climate conditions.

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  • MONITOR: Mitigation of Natural Incidence Towards an increased Oceanic Resilience [Poster]

    MONITOR (Second Institute of Oceanography, MNR, 2023)
    The proposed project will make contributions to marine natural disaster prevention of countries in the Indo-Pacific region. The project will have major focus on education and intelligent collaborations among young scientists. There will be summer course being offered to students from all participating institutions every year, together with personnel exchange program. The technology for developing regional physical-biological modeling will be introduced and the operational forecasting systems for regional environments are expected to be developed in the coastal regions along the Indian and western Pacific Ocean.
  • Oceano sem mistérios : Construindo cidades azuis

    Bumbeer, Janaina; Baladelli Ribeiro, Juliana; Alberti, Liziane; Leopoldi, Giovanna; Adriano Christofoletti, Ronaldo; Keiko Takahashi, Camila; Eon, Fábio; de Pinho, Roberto (Conexao Oceano, 2023)
    Cidade Azul é aquela que promove a sustentabilidade - social, ambiental, econômica, cultural e em sua governança - integrando políticas públicas e ações de cidadãos e instituições com o oceano. Portanto, ser uma cidade azul é fortalecer a relação da sustentabilidade com o oceano! E não importa a distância do mar, mesmo cidades do interior podem, e devem, ser azuis. A cultura oceânica é definida como o “entendimento da influência do oceano em nossas vidas e de nossas ações no oceano”, no qual “nós” corresponde a indivíduos e instituições, sejam elas públicas ou privadas. Ela é feita com todos os diferentes setores da sociedade, considerando suas especificidades locais e de forma integrada e colaborativa. É importante pontuar que este documento não traz uma fórmula única ou guia para uma Cidade Azul, pois cada cidade possui sua realidade social, cultural, ambiental, econômica e de infraestrutura política e administrativa. Este documento também não busca iniciar ou trazer novas demandas, mas sim inserir uma lente azul nas iniciativas, projetos e ações já realizadas ou em andamento, valorizando e ampliando o impacto destas ações. Aqui, você vai encontrar estratégias divididas em sete esferas principais - educação, economia azul sustentável, turismo, adaptação, água e saneamento, saúde e bem- estar e conservação - que podem ser adotadas de forma conjunta ou individualmente. Todas elas dialogam e ajudam seu município a alcançar os Objetivos de Desenvolvimento Sustentável da Agenda 2030, além de responder aos Desafios da Década da Ciência Oceânica para o Desenvolvimento Sustentável (2021 - 2030). Tomadores de decisão, servidores públicos dos municípios e Estados, este é um convite e oportunidade para discutir, adaptar e aplicar os caminhos aqui apresentados e, assim, construir sua cidade azul.
  • At-sea application of the comet assay to a deep-sea fish

    Hartl, Mark G.J.; Baumann, Lukas M.; Sweetman, Andrew K. (2024)
    Deep-Sea Research Part I
    Given the go ahead, deep-sea mining operations are likely to continue for decades on a substantial spatial scale and the resulting sediment plumes combined, are likely to extend beyond the licenced mining areas, and could lead to the chronic exposure of deep-sea organisms to a mixture of metals, even mobile species, such as fish, that could conceivably display avoidance behaviour. The metal concentrations, often substantially below lethal doses, mean that individual mortality is too blunt a measure to allow assessment of “serious harm”. Commonly used cellular biomarkers of exposure in ecotoxicology include DNA damage using the Comet assay. True deep-sea ecotoxicological studies with fish are rare and to our knowledge, there are no published data or method optimizations for deep-sea fish. Coryphaenoides ssp. were collected during SMARTEX expedition 1 (Feb/Mar, 2023) to the Clarion Clipperton Zone (CCZ) in the Eastern Pacific Ocean using a baited trap deployed between 4580–4,732m depth for 24–48 h. Blood and gill tissue were removed and processed for the Comet assay. In order to reduce artefactual DNA damage from cryopreservation observed previously, two sets of samples were prepared: a cryopreservative (10% DMSO) was added to one set of samples and stored at − 80 ◦C; the second set was used to perform a Comet assay within hours of collection. A custom-built gimble table enabled horizontal electrophoresis at sea after which Comet assay slides were dried and stored at room temperature until further analysis. The Comet assay was also assessed in freshly sampled and frozen rainbow trout cells as a proxy control in order to evaluate potential artefacts from the collection and sampling procedure of the deep-sea fish. The blood samples processed at sea had a significantly reduced level of DNA damage compared to the frozen samples. There was no significant difference between the fresh deep-sea and rainbow trout samples. However, the freshly prepared gill samples in Coryphaenoides ssp. showed substantial artefacts, possibly as a consequence of barotrauma. These results represent the first effort at establishing baseline DNA damage data for deep-sea fish, an essential component in understating and quantifying the impact of deep-sea mining.
  • Transport inventories and exchanges of organic matter throughout the St. Lawrence Estuary continuum (Canada)

    Lévesque, David; Lebeuf, Michel; Maltais, Domynick; Anderson, Caroline; Starr, Michel (2023)
    Frontiers in Marine Science
    Hypoxia (O2 < 2 mg/L) driven by eutrophication in estuaries and shelves is a worldwide expanding problem. The role of organic matter (OM) inputs is emerging as an important contributor to this issue, beside the well-known implication of inorganic nutrients. The St. Lawrence Estuary, one of the largest and deepest estuarine system in the world is facing strong persistent and increasing hypoxia. In this context, transport and exchange of particulate and dissolved organic matter (POM and DOM, respectively) were investigated as a first step to understand their implication in hypoxia. Tributaries and Gulf contributions were compared to St. Lawrence Estuary inventories for the spring freshet (May), the summer low-flow (August), and the fall-mixing (October). Furthermore, changes in OM ratios were examined along the estuarine gradient from the upper St. Lawrence Estuary (USLE), downstream of the maximum turbidity zone, to the lower estuary (LSLE). For the USLE, net transport was always positive and net export/loading ratios suggested that 64–90% of POM and 30–63% of DOM were either retained or transformed during its course from tributaries to LSLE. Net transport from the USLE toward the LSLE was 3–13 fold more important in May than in August or October. For the LSLE, net transport to the Gulf was generally negative meaning that OM production was the dominating proces. The extremely high net export/loading ratios in August indicate that POM production was 28.8 to 41.4 times the combined inputs of tributaries and Gulf. Net export/loading ratios remained superior to one during May and October (1.7–9.4) for the LSLE. Changes along the upstream–downstream continuum were seen for POM, with a steady increase relative to total suspended matter from 7.3% to 50.2%, but they were not observed for DOM, for which no obvious trends were detected. Our results highlight the importance of explicitly considering OM in eutrophication monitoring programs of the St. Lawrence Estuary, as the mineralisation of a portion of the large OM pool size could influence our understanding of hypoxia and acidification of the deep waters of LSLE.
  • Introduction to the Workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)"

    Kirchner, Andree; Schiano di Pepe, Lorenzo; ISRIM; University of Genoa (ISRIM; University of Genoa, 2023)
    In the first part of the introductory video (1/6), Prof. Dr. Andree Kirchner (@ISRIM) and Prof. Dr. Lorenzo Schiano di Pepe (@Uni.Genova) are giving some background information about the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)". In the second part of the introductory video, Prof. Dr. Marco Giovine (Centro del Mare, @Uni.Genova) explains the importance of the topic from the perspective of the Centre of the Sea at the University of Genoa. The presentations are part of the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)", which took place in the framework of the 9th Summer School on the European Union and the Law of the Sea (EULoS). It was organized by the Institute for the Law of the Sea and International Marine Environmental Law (ISRIM) and the University of Genoa on 1 September 2023. The workshop is an UN Ocean Decade Activity.
  • Capacity-Building and the Transfer of Marine Technology

    Grainger, Carl; ISRIM; University of Genoa (2023)
    In the sixth video (6/6) of the series, Mr Carl Grainger (Department of Foreign Affairs, Ireland) explains the provisions of Part V on "Capacity-building and the transfer of marine technology" of the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ Agreement), which was adopted on 19 June 2023 in New York. The presentation is part of the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)", which took place in the framework of the 9th Summer School on the European Union and the Law of the Sea (EULoS). It was organized by the Institute for the Law of the Sea and International Marine Environmental Law (@ISRIM ) and the University of Genoa (@Uni.Genova ) on 1 September 2023. The workshop is a UN Ocean Decade Activity.
  • Environmental Impact Assessments

    Lindström Battle, Jessica; ISRIM; University of Genoa (Universita di Genova, Institutie for the Law of the Sea and International Marine Environmental Law, 2023)
    In the fifth video (5/6) of the series, Ms. Jessica Lindström Battle (@WWF) the provisions of Part IV on "Environmental impact assessments" of the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ Agreement), which was adopted on 19 June 2023 in New York. The presentation is part of the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)", which took place in the framework of the 9th Summer School on the European Union and the Law of the Sea (EULoS). It was organized by the Institute for the Law of the Sea and International Marine Environmental Law (@ISRIM) and the University of Genoa (@Uni.Genova) on 1 September 2023. The workshop is a UN Ocean Decade Activity.
  • Measures such as Area-based Management Tools, Including Marine Protected Areas

    Becker-Weinberg, Vasco; ISRIM; University of Genoa (Universita di Genova, Institutie for the Law of the Sea and International Marine Environmental Law, 2023)
    In the fourth video (4/6) of the series, Prof. Dr. Vasco Becker-Weinberg (New University of Lisbon) explains the provisions of Part III on "Measures such as area-based management tools, including marine protected areas" of the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ Agreement), which was adopted on 19 June 2023 in New York. The presentation is part of the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)", which took place in the framework of the 9th Summer School on the European Union and the Law of the Sea (EULoS). It was organized by the Institute for the Law of the Sea and International Marine Environmental Law (@ISRIM ) and the University of Genoa (@Uni.Genova) on 1 September 2023. The workshop is a UN Ocean Decade Activity.
  • The new BBNJ Agreement.

    Kirchner, Andree; ISRIM; University of Genoa (Universita di Genova, Institute for the Law of the Sea and International Marine Environmental Law, 2023)
    In the second video (2/6) of the series, Prof. Dr. Andree Kirchner (ISRIM) explains the historical background of the initiative and the negotiation processes, which lead to the adoption of the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ Agreement) on 19 June 2023 in New York. The presentation is part of the workshop "Conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ)", which took place in the framework of the 9th Summer School on the European Union and the Law of the Sea (EULoS). It was organized by the Institute for the Law of the Sea and International Marine Environmental Law (ISRIM) and the University of Genoa on 1 September 2023. The workshop is a UN Ocean Decade Activity.
  • Addressing underwater noise in Europe: Current state of knowledge and future priorities

    Thomsen, Frank; Mendes, Sónia; Bertucci, Frédéric; Breitzke, Monika; Ciappi, Elena; Cresci, Alessandro; Debusschere, Elisabeth; Ducatel, Cecile; Folegot, Thomas; Juretzek, Carina; et al. (European Marine Board, 2021)
    The Ocean presents a cacophony of sounds originating from natural as well as anthropogenic sources. Marine organisms heavily rely on sound to communicate and understand the world around them, and are therefore potentially impacted by anthropogenic sound. However, in developing our Blue Economy and in advancing our knowledge of marine environments and ecosystems, anthropogenic noise is sometimes unavoidable. Understanding the potential effects of anthropogenic noise is therefore integral to addressing this conflict, as it is needed to develop proportionate mitigation strategies and effective regulation. Next to providing an overview of our current knowledge about underwater noise, this publication highlights the priority areas for further research addressing the remaining knowledge gaps about the effects of anthropogenic noise. Furthermore, it points out the relevant actions needed to take in order to ensure ecosystem-based and precautionary legislation.
  • Every map lies - A geohistorical approach to wetland restoration: ancient maps and modern geospatial technologies for a source-to-sea perspective in the Pantanello Natural Park and surrounding designated areas

    Gaglioti, Martina (Self Published, 2023)
    This study has been conceived after a field-based experience and developing the wider analysis through a geohistorical approach, according to the need to deepen the scientific knowledge of a portion of land characterized by a relevant habitat complexity and species diversity, despite its limited spatial extension. One of the main objectives of this study is to describe the changes in the land use, over approximately 150 years in an Italian agricultural landscape, in relation to changes in human population, livestock and wildlife species, to analyze the relationships between historical land use, current species diversity and upcoming uses of the natural resources within the area.
  • Marine Genetic Resources: An Intellectual Property Perspective.

    Kirchner-Freis, Iris; Kirchner, Andree (Hugo Grotius Publishers, 2023)
    After about 20 years of negotiations in different fora, the United Nations (UN) adopted on 19 June 2023 the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ Agreement). The BBNJ Agreement is intended to ensure conservational and sustainable use of marine biodiversity in areas beyond national jurisdiction. Part II of the new BBNJ Agreement deals with marine genetic resources (MGRs) of areas beyond national jurisdiction, i.e. the high seas and the Area (Art. 1(2), BBNJ Agreement), the digital sequence information (DSI) on MGRs, and the fair and equitable sharing of the benefits arising from their utilization.
  • Unexpected incomers in the Asterousia Biosphere Reserve: The shy swim of Torquigener flavimaculosus cubs along our boat line an the beached hints of Lagocephalus onshore

    Gaglioti, Martina (2023)
    This contribution is the outcome of a field-based observation occurred in the shallow waters of the Asterousia Biosphere Reserve on the southern coast of Creete Island. The occurrence of two IAS highlighted and confirmed the presence of Lessepsian immigrants in the area.
  • Ocean oxygen: The role of the Ocean in the oxygen we breathe and the threat of deoxygenation

    Grégoire, Marilaure; Oschlies, Andreas; Canfield, Donald; Castro, Carmen; Ciglenečki, Irena; Croot, Peter; Salin, Karine; Schneider, Birgit; Serret, Pablo; Slomp, Caroline; et al. (European Marine Board, 2023)
    EMB Future Science Brief No. 10 highlights the most recent science on Ocean oxygen, including causes, impacts and mitigation strategies of Ocean oxygen loss, and discusses whether “every second breath we take comes from the Ocean”. It closes with key policy, management and research recommendations to address Ocean deoxygenation and communicate more accurately about the role of the Ocean in Earth’s oxygen. The sentence “every second breath you take comes from the Ocean” is commonly used in Ocean Literacy and science communication to highlight the importance of Ocean oxygen. However, despite its widespread use, it is often not phrased correctly. In contrast, there is little awareness about the threat of the global oxygen loss in the Ocean, called deoxygenation, particularly in comparison with other important stressors, such as Ocean acidification or increasing seawater temperatures. Deoxygenation is increasing in the coastal and open Ocean, primarily due to human-induced global warming and nutrient run-off from land, and projections show that the Ocean will continue losing oxygen as global warming continues. The consequences of oxygen loss in the Ocean are extensive and include decreased biodiversity, shifts in species distributions, displacement or reduction in fisheries resources, changes in biogeochemical cycling and mass mortalities. Low oxygen conditions also drive other chemical processes which produce greenhouse gases, toxic compounds and further degrade water quality. The degraded water quality directly affects marine ecosystems, but also indirectly impacts ecosystem services supporting local communities, regional economies and tourism. Although there are still gaps in our knowledge, we know enough to be very concerned about the consequences: the impacts might even be larger than from Ocean acidification or heat waves, and three out of the five global mass extinctions were linked to Ocean deoxygenation. The sense of urgency to improve Ocean health is reflected in the UN Decade of Ocean Science for Sustainable Development (Ocean Decade) and the EU Mission: Restore our Ocean and Waters (Mission Ocean), and tackling the loss of oxygen in the Ocean is critical to achieving the aims of these two initiatives.
  • Blue Carbon: Challenges and opportunities to mitigate the climate and biodiversity crises

    Gattuso, Jean-Pierre; Hicks, Natalie; Neukermans, Griet; Landschützer, Peter; Pörtner, Hans-Otto; Heymans, Sheila JJ; Heymans, Sheila JJ; Rodriguez Perez, Ana; Alexander, Britt; Muñiz Piniella, Ángel; et al. (European Marine Board, 2023)
    Climate change and biodiversity loss are two of humanity’s greatest challenges. Blue carbon, i.e. the carbon captured and stored by marine living organisms and ecosystems, has the potential to help mitigate both challenges, because marine ecosystems that are important for sequestering carbon often also harbour rich biodiversity. Expanding and protecting Blue Carbon ecosystems has therefore been proposed as a Nature-based Solution to complement climate change mitigation efforts on land and to protect and restore marine biodiversity. In addition, securing and rebuilding Blue Carbon ecosystems can stabilise livelihoods, protect coasts, and support other societal needs such as food provision from the Ocean. However, the effectiveness of Blue Carbon ecosystems as a Nature-based Solution depends on the available space and ecosystem productivity, which can be impacted by climate change. Moreover, the overall carbon sequestration potential of Blue Carbon ecosystems is low and their contribution to climate stabilisation will only be significant once greenhouse gas emissions are strongly limited. Therefore, a drastic reduction of greenhouse gas emissions to keep global warming close to 1.5°C above pre-industrial levels is essential to maintain the health and long-term functionality of Blue Carbon ecosystems as a Nature-based Solution. This document describes examples and benefits of Blue Carbon ecosystems, and discusses uncertainties and challenges for the conservation and restoration of Blue Carbon ecosystems as a climate change solution. It also highlights the wider role of the Ocean in mitigating climate change through the carbon cycle, and closes with key research and management recommendations.
  • Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise).

    van Horsten, Natasha René; Planquette, Hélène; Sarthou, Géraldine; Ryan-Keogh, Thomas James; Lemaitre, Nolwenn; Mtshali, Thato Nicholas; Roychoudhury, Alakendra; Bucciarelli, Eva (2022)
    Biogeosciences
    he Southern Ocean (SO) is of global importance to the carbon cycle, and processes such as mesopelagic remineralisation that impact the efficiency of the biological carbon pump in this region need to be better constrained. During this study early austral winter barium excess (Baxs) concentrations were measured for the first time, along 30∘ E in the southern Indian Ocean. Winter Baxs concentrations of 59 to 684 pmol L−1 were comparable to those observed throughout other seasons. The expected decline of the mesopelagic Baxs signal to background values during winter was not observed, supporting the hypothesis that this remineralisation proxy likely has a longer timescale than previously reported. A compilation of available SO mesopelagic Baxs data, including data from this study, shows an accumulation rate of ∼0.9 µmol m−2 d−1 from September to July that correlates with temporally integrated remotely sensed primary productivity (PP) throughout the SO from data spanning ∼20 years, advocating for a possible annual timescale of this proxy. The percentage of mesopelagic particulate organic carbon (POC) remineralisation as calculated from estimated POC remineralisation fluxes over integrated remotely sensed PP was ∼2-fold higher south of the polar front (19 ± 15 %, n=39) than north of the polar front (10 ± 10 %, n=29), revealing the higher surface carbon export efficiency further south. By linking integrated remotely sensed PP to mesopelagic Baxs stock, we could obtain better estimates of carbon export and remineralisation signals within the SO on annual and basin scales.
  • An indicator of sea ice variability for the Antarctic marginal ice zone.

    Vichi, Marcello (2022)
    The Cryosphere
    Remote-sensing records over the last 40 years have revealed large year-to-year global and regional variability in Antarctic sea ice extent. Sea ice area and extent are useful climatic indicators of large-scale variability, but they do not allow the quantification of regions of distinct variability in sea ice concentration (SIC). This is particularly relevant in the marginal ice zone (MIZ), which is a transitional region between the open ocean and pack ice, where the exchanges between ocean, sea ice and atmosphere are more intense. The MIZ is circumpolar and broader in the Antarctic than in the Arctic. Its extent is inferred from satellite-derived SIC using the 15 %–80% range, assumed to be indicative of open drift or partly closed sea ice conditions typical of the ice edge. This proxy has been proven effective in the Arctic, but it is deemed less reliable in the Southern Ocean, where sea ice type is unrelated to the concentration value, since wave penetration and free-drift conditions have been reported with 100% cover. The aim of this paper is to propose an alternative indicator for detecting MIZ conditions in Antarctic sea ice, which can be used to quantify variability at the climatological scale on the ice-covered Southern Ocean over the seasons, as well as to derive maps of probability of encountering a certain degree of variability in the expected monthly SIC value. The proposed indicator is based on statistical properties of the SIC; it has been tested on the available climate data records to derive maps of the MIZ distribution over the year and compared with the threshold-based MIZ definition. The results present a revised view of the circumpolar MIZ variability and seasonal cycle, with a rapid increase in the extent and saturation in winter, as opposed to the steady increase from summer to spring reported in the literature. It also reconciles the discordant MIZ extent estimates using the SIC threshold from different algorithms. This indicator complements the use of the MIZ extent and fraction, allowing the derivation of the climatological probability of exceeding a certain threshold of SIC variability, which can be used for planning observational networks and navigation routes, as well as for detecting changes in the variability when using climatological baselines for different periods.
  • Using seabird and whale distribution models to estimate spatial consumption of krill to inform fishery management.

    Warwick-Evans, V.; Kelly, N.; Dalla Rosa, L.; Friedlaender, A.; Hinke, J. T.; Kim, J. H.; Kokubun, N.; Santora, J. A.; Secchi, E. R.; Seyboth, E.; et al. (2022)
    Ecosphere
    Ecosystem dynamics at the northwest Antarctic Peninsula are driven by interactions between physical and biological processes. For example, baleen whale populations are recovering from commercial harvesting against the backdrop of rapid climate change, including reduced sea ice extent and changing ecosystem composition. Concurrently, the commercial harvesting of Antarctic krill is increasing, with the potential to increase the likelihood for competition with and between krill predators and the fishery. However, understanding the ecology, abundance, and spatial distribution of krill predators is often limited, outdated, or at spatial scales that do not match those desired for effective fisheries management. We update current knowledge of predator dependence on krill by integrating telemetry-based data, at-sea observational surveys, estimates of predator abundance, and physiological data to estimate the spatial distribution of krill consumption during the austral summer by three species of Pygoscelis penguin, 11 species of flying seabirds, one species of pinniped, and two species of baleen whale. Our models show that the majority of important areas for krill predator foraging are close to penguin breeding colonies in nearshore areas where humpback whales also regularly feed, and along the shelf-break, though we caution that not all known krill predators are included in these analyses. We show that krill consumption is highly variable across the region, and often concentrated at fine spatial scales, emphasizing the need for the management of the local krill fishery at relevant temporal and spatial scales. We also note that krill consumption by recovering populations of krill predators provides further evidence in support of the krill surplus hypothesis, and highlight that despite less than comprehensive data, cetaceans are likely to consume a significant proportion of the krill consumed by natural predators but are not currently considered directly in the management of the krill fishery. If management of the krill fishery is to be precautionary and operate in a way that minimizes the risks to krill predator populations, it will be necessary in future analyses, to include up-to-date and precise abundance and consumption estimates for pack-ice seals, finfish, squid, and other baleen whale species not currently considered.
  • Determination of Trace Metal (Mn, Fe, Ni, Cu, Zn, Co, Cd and Pb) Concentrations in Seawater Using Single Quadrupole ICP-MS: A Comparison between Offline and Online Preconcentration Setups.

    Samanta, Saumik; Cloete, Ryan; Loock, Jean; Rossouw, Riana; Roychoudhury, Alakendra N. (2021)
    Minerals
    The quantification of dissolved metals in seawater requires pre-treatment before the measurement can be done, posing a risk of contamination, and requiring a time-consuming procedure. Despite the development of automated preconcentration units and sophisticated instruments, the entire process often introduces inaccuracies in quantification, especially for low-metal seawaters. This study presents a robust method for measuring dissolved metals from seawater accurately and precisely using a seaFAST and quadrupole Inductively Coupled Plasma Mass Spectrometer (ICPMS), employed in both offline (2016–2018) and online (2020–2021) setups. The proposed method shows data processing, including the re-calculation of metals after eliminating the instrumental signals caused by polyatomic interferences. Here, we report the blank concentration of Fe below 0.02 nmol kg−1, somewhat lower values than that have been previously reported using high-resolution and triple-quad ICPMS. The method allows for the accurate determination of Cd and Fe concentrations in low-metal seawaters, such as GEOTRACES GSP, using a cost-effective quadrupole ICPMS (Cdconsensus: 2 ± 2 pmol kg−1, Cd measured: 0.99 ± 0.35 pmol kg−1; Fe consensus: 0.16 ± 0.05 nmol kg−1, Fe measured: 0.21 ± 0.03 nmol kg−1). Between two setups, online yields marginally lower blank values for metals based on short-term analysis. However, the limit of detection is comparable between the two, supporting optimal instrumental sensitivity of the ICPMS over 4+ years of analysis.
  • Combining Regional Habitat Selection Models for Large-Scale Prediction: Circumpolar Habitat Selection of Southern Ocean Humpback Whales.

    Reisinger, Ryan R.; Friedlaender, Ari S.; Zerbini, Alexandre N.; Palacios, Daniel M.; Andrews-Goff, Virginia; Dalla Rosa, Luciano; Double, Mike; Findlay, Ken; Garrigue, Claire; How, Jason; et al. (2021)
    Remote Sensing
    Machine learning algorithms are often used to model and predict animal habitat selection— the relationships between animal occurrences and habitat characteristics. For broadly distributed species, habitat selection often varies among populations and regions; thus, it would seem preferable to fit region- or population-specific models of habitat selection for more accurate inference and prediction, rather than fitting large-scale models using pooled data. However, where the aim is to make range-wide predictions, including areas for which there are no existing data or models of habitat selection, how can regional models best be combined? We propose that ensemble approaches commonly used to combine different algorithms for a single region can be reframed, treating regional habitat selection models as the candidate models. By doing so, we can incorporate regional variation when fitting predictive models of animal habitat selection across large ranges. We test this approach using satellite telemetry data from 168 humpback whales across five geographic regions in the Southern Ocean. Using random forests, we fitted a large-scale model relating humpback whale locations, versus background locations, to 10 environmental covariates, and made a circumpolar prediction of humpback whale habitat selection. We also fitted five regional models, the predictions of which we used as input features for four ensemble approaches: an unweighted ensemble, an ensemble weighted by environmental similarity in each cell, stacked generalization, and a hybrid approach wherein the environmental covariates and regional predictions were used as input features in a new model. We tested the predictive performance of these approaches on an independent validation dataset of humpback whale sightings and whaling catches. These multiregional ensemble approaches resulted in models with higher predictive performance than the circumpolar naive model. These approaches can be used to incorporate regional variation in animal habitat selection when fitting range-wide predictive models using machine learning algorithms. This can yield more accurate predictions across regions or populations of animals that may show variation in habitat selection.

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