Posts Tagged 'review'

A fine kettle of fish: the fishing industry and environmental impacts

Highlights

• Most fishing stocks are still being exploited above sustainable levels.

• Oceans are acting as sinks for numerous human-generated environmental hazards.

• Nutrient loading or microplastics are direct threats to the quality of fish stocks.

• Climate change is rapidly changing ecological dynamics in world oceans.

• Adaptive management is needed to meet seafood demand and global food security.

Abstract

Overexploitation or full exploitation of fishing stocks first became an important problem in the second half of the 20th century, with certain fisheries collapsing and others being exploited in an unsustainable manner. This situation led to dwindling fish landings worldwide, although final seafood demand has not suffered this decrease thanks to the growth of aquaculture. Currently, new threats to marine biota are emerging that could ultimately lead to further stress on fishing stocks. The current opinion paper explores these growing threats, which include the spread of dead zones throughout coastal areas, marine litter, especially micro- and nanoplastics that are ingested by marine organisms and ultimately by humans, or the effects of climate change on world oceans, including acidification due to carbon dioxide absorption from the atmosphere or alteration in ocean circulation due to melting glaciers. Consequently, it is critical for stakeholders in the fishing sector to gain awareness of what is at stake in the upcoming decades. In fact, not only will fisheries have to expand their approach from single-species stock assessment to ecosystem-based approaches, but other metrics will have to be brought forward to maintain competitiveness and minimize food security concerns.

Continue reading ‘A fine kettle of fish: the fishing industry and environmental impacts’

La terminologie de la géoingénierie marine. Une contribution au projet IATE-CvT (in French)

Pour la première fois mentionnée dans la politique en 1965 par le comité consultatif scientifique du président des États-Unis, la géoingénierie (ou : ingénierie climatique) est une préoccupation relativement nouvelle. Plus de cinquante ans plus tard, le sujet reste néanmoins une topique controversée. La question reste : jusqu’où peut-on intervenir dans le climat afin de contrebalancer le changement climatique d’origine anthropocène ? La géoingénierie fait référence aux techniques développées pour lutter contre le changement climatique en supprimant les gaz à effet de serre de l’atmosphère de l’un côté et de l’autre en augmentant la quantité de lumière solaire réfléchie vers l’espace à partir de la terre et des océans (Shepherd, J. G. 2009). C’est un domaine actuel qui peut éventuellement impliquer chacun sur terre. Le domaine se trouve au cœur de nombreux sommets internationaux (p. ex. le COP21 de 2015 à Paris) et suscite non seulement des questions au niveau de la technologie, mais également au niveau éthique (jusqu’où peut-on altérer la nature ?), politique (protocole de Kyoto, 1997), philosophique (« on est Dieu »), sociologique (les conséquences pour les habitants), biologique (les conséquences pour les espèces) et économique (qui paye ?). Comme la géoingénierie est une préoccupation relativement nouvelle, la terminologie internationale laisse encore à désirer. Le domaine étant en pleine voie de développement, les scientifiques du domaine ne se préoccupent guère avec les mots qu’ils appliquent. Reste la tâche aux terminologues de décrire, nommer et normer les termes. Dans ce travail sont traités dix termes venant de la géoingénierie marine. Les termes ont été rencontrés dans des publications scientifiques anglaises, puis décrits en anglais, français et néerlandais de manière à les intégrer dans les bases de données terminologiques IATE et la base terminologique du Centrum voor Terminologie (CvT ; Centre pour Terminologie).

Continue reading ‘La terminologie de la géoingénierie marine. Une contribution au projet IATE-CvT (in French)’

A status review of pinto abalone (Haliotis kamtschatkana) along the west coast of North America: interpreting trends, addressing uncertainty, and assessing risk for a wide-ranging marine invertebrate

Pinto abalone (Haliotis kamtschatkana), the widest ranging abalone species in North America, occurs from Alaska, United States to Central Baja California, Mexico. The species has been observed in intertidal and subtidal habitats from 0 to 40mdepth. The best available data indicate that pinto abalone abundance has declined in many areas throughout the species’ range due to fisheries harvest. Subsistence and personal use fisheries in Alaska and a commercial fishery in Mexico persist. Preliminary data from 2008 to 2016 indicate signs of recovery for some pinto abalone populations along the British Columbia coast due to multiple contributing factors including a reduction in illegal harvest, natural recovery following fishery closure, and low predation pressure. By contrast, pinto abalone populations at the San Juan Islands in Washington are experiencing recruitment failure and continuing to decline, despite closure of the fisheries and no evidence of poaching. Throughout the remainder of the species’ range, trends are less clear, due to the lack of regular, long-term monitoring surveys for pinto abalone. The limited data from surveys and/or opportunistic sightings indicate that pinto abalone populations are small, patchily distributed, and/or fluctuate episodically in Alaska, California, and Mexico, with evidence of recent recruitment in a number of locations within these three areas. Baseline abundance and trend data for the species before the advent of commercial fisheries and, in some areas, the local extirpation of sea otters is lacking. Without a clear baseline with which to compare the current abundance levels and trend information, it is difficult to interpret what these levels mean for the status and viability of the species. Threats to pinto abalone were evaluated and characterized using a qualitative rating (i.e., low, moderate, high, very high) based on the threats’ scope, severity, and persistence and the sufficiency of the data to support the rating. Several threats that posed a moderate level of risk to pinto abalone were identified including the following: low densities as a result of historical overfishing; the potential threat posed by ocean acidification; and illegal take because of poaching and inadequate law enforcement. The overall risk that pinto abalone face throughout their range was evaluated, and it was determined that they have a low to moderate level of extinction risk now and in the foreseeable future (over both the 30-y and 100-y time horizons). There is a high level of uncertainty regarding demographic factors, in particular regarding whether abundance and productivity levels are sufficient to support the persistence and recovery of the species in the face of continuing and potential future threats. Although recruitment failure may be occurring in some areas (e.g., San Juan Islands Archipelago), in other areas throughout the range recurring and/or recent recruitment events have been observed, despite low densities, and have even resulted in increased densities (across all size classes) at several index sites in British Columbia. Limitations in using demographic data to guide conservation actions and help ensure species persistence could be overcome by conducting consistent monitoring of pinto abalone populations throughout their range.

Continue reading ‘A status review of pinto abalone (Haliotis kamtschatkana) along the west coast of North America: interpreting trends, addressing uncertainty, and assessing risk for a wide-ranging marine invertebrate’

Algal communities: an answer to global climate change

Human activities and resultant changes in global climate have profound consequences for ecosystems and economic and social systems, including those that are dependent upon marine systems. The increasing concentration of atmospheric greenhouse gases (GHGs) has resulted in gradual modification of multiple aspects of marine ecosystem properties such as salinity, temperature, and pH. It is well known that temporal and spatial variations in environmental properties determine the composition and abundance of different algal populations in a region. Within the present study the evidence for algal compatibility to changing environmental conditions is surveyed. The unique ability of algal communities to play a role in promotion of CO2 sequestration technologies, biorefinery approaches, as well as transition to CO2‐neutral renewable energy has gained traction with environmentalists and economists in a view to mitigation of climate change using algae. The next step is to re‐evaluate the assumption of a steady‐state oceanic carbon cycle and the role of biological activities in response to future climate changes.

Continue reading ‘Algal communities: an answer to global climate change’

Critically examining the knowledge base required to mechanistically project climate impacts: a case study of Europe’s fish and shellfish

An amalgam of empirical data from laboratory and field studies is needed to build robust, theoretical models of climate impacts that can provide science‐based advice for sustainable management of fish and shellfish resources. Using a semi‐systematic literature review, Gap Analysis and multilevel meta‐analysis, we assessed the status of empirical knowledge on the direct effects of climate change on 37 high‐value species targeted by European fisheries and aquaculture sectors operating in marine and freshwater regions. Knowledge on potential climate change‐related drivers (single or combined) on several responses (vital rates) across four categories (exploitation sector, region, life stage, species), was considerably unbalanced as well as biased, including a low number of studies (a) examining the interaction of abiotic factors, (b) offering opportunities to assess local adaptation, (c) targeting lower‐value species. The meta‐analysis revealed that projected warming would increase mean growth rates in fish and mollusks and significantly elevate metabolic rates in fish. Decreased levels of dissolved oxygen depressed rates of growth and metabolism across coherent species groups (e.g., small pelagics, etc.) while expected declines in pH reduced growth in most species groups and increased mortality in bivalves. The meta‐analytical results were influenced by the study design and moderators (e.g., life stage, season). Although meta‐analytic tools have become increasingly popular, when performed on the limited available data, these analyses cannot grasp relevant population effects, even in species with a long history of study. We recommend actions to overcome these shortcomings and improve mechanistic (cause‐and‐effect) projections of climate impacts on fish and shellfish.

Continue reading ‘Critically examining the knowledge base required to mechanistically project climate impacts: a case study of Europe’s fish and shellfish’

Ocean acidification refugia in variable environments

Climate change refugia in the terrestrial biosphere are areas where species are protected from global environmental change and arise from natural heterogeneity in landscapes and climate. Within the marine realm, ocean acidification, or the global decline in seawater pH, remains a pervasive threat to organisms and ecosystems. Natural variability in seawater carbon dioxide (CO2) chemistry, however, presents an opportunity to identify ocean acidification refugia (OAR) for marine species. Here, we review the literature to examine the impacts of variable CO2 chemistry on biological responses to ocean acidification and develop a framework of definitions and criteria that connects current OAR research to management goals. Under the concept of managing vulnerability, the most likely mechanisms by which OAR can mitigate ocean acidification impacts are by reducing exposure to harmful conditions or enhancing adaptive capacity. While local management options, such as OAR, show some promise, they present unique challenges, and reducing global anthropogenic CO2 emissions must remain a priority.

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Observing changes in ocean carbonate chemistry: our autonomous future

Our developing network of autonomous carbonate observations is currently targeted at surface ocean CO2 fluxes and compact ecosystem observatories. New integration of developed sensors on gliders and surface vehicles will increase our coastal and regional observational capability. Most autonomous platforms observe a single carbonate parameter, which leaves us reliant on the use of empirical relationships to constrain the rest of the carbonate system. Sensors now in development promise the ability to observe multiple carbonate system parameters from a range of vehicles in the near future.

Continue reading ‘Observing changes in ocean carbonate chemistry: our autonomous future’


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OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book