47 posts tagged with "Climate Change"

Translating the Paris Agreement to limit global warming to 1.5°C above preindustrial level into impact-related targets facilitates communication of the benefits of mitigating climate change to policy-makers and stakeholders. Developing ecologically relevant impact-related targets for marine ecosystem services, such as fisheries, is an important step. Here, we use maximum catch potential and species turnover as climate-risk indicators for fisheries. We project that potential catches will decrease by more than 3 million metric tons per degree Celsius of warming. Species turnover is more than halved when warming is lowered from 3.5° to 1.5°C above the preindustrial level. Regionally, changes in maximum catch potential and species turnover vary across ecosystems, with the biggest risk reduction in the Indo-Pacific and Arctic regions when the Paris Agreement target is achieved.

There is a critical need to develop effective strategies for the long-term sustainability of Canada’s oceans. However, this is challenged by uncertainty over future impacts of global environmental and socioeconomic change on marine ecosystems, and how coastal communities will respond to these changes. Scenario analysis can address this uncertainty by exploring alternative futures for Canadian oceans under different pathways of climate change, economic development, social and policy changes. However, there has, to date, been no scenario analysis of Canada’s future ocean sustainability at a national scale. To facilitate this process, we review whether the literature on existing scenarios of Canada’s fisheries and marine ecosystems provides an integrative, social-ecological perspective about potential future conditions. Overall, there is sufficient national-level oceanographic data and application of ecosystem, biophysical, and socioeconomic models to generate projections of future ocean and socioeconomic trends in Canada. However, we find that the majority of marine-related scenario analyses in Canada focus on climate scenarios and the associated oceanographic and ecological changes. There is a gap in the incorporation of social, economic, and governance drivers in scenarios, as well as a lack of scenarios which consider the economic and social impact of future change. Moreover, available marine scenario studies mostly do not cover all three Canadian oceans simultaneously. To address these gaps, we propose to develop national-level scenarios using a matrix framework following the concept of Shared Socioeconomic Pathways, which would allow a social-ecological examination of Canada’s oceans in terms of the state of future uncertainties.

Assessments of the combined ecological impacts of ocean acidification and warming (OAW) and their social and economic consequences can help develop adaptive and responsive management strategies in the most sensitive regions. Here, available observational and experimental data, theoretical, and modelling approaches are combined to project and quantify potential effects of OAW on the future fisheries catches and resulting revenues and employment in the UK under different CO2 emission scenarios. Across all scenarios, based on the limited available experimental results considered, the bivalve species investigated were more affected by OAW than the fish species considered, compared with ocean warming alone. Projected standing stock biomasses decrease between 10 and 60%. These impacts translate into an overall fish and shellfish catch decrease of between 10 and 30% by 2020 across all areas except for the Scotland >10 m fleet. This latter fleet shows average positive impacts until 2050, declining afterwards. The main driver of the projected decreases is temperature rise (0.5–3.3 °C), which exacerbate the impact of decreases in primary production (10–30%) in UK fishing waters. The inclusion of the effect of ocean acidification on the carbon uptake of primary producers had very little impact on the projections of potential fish and shellfish catches (<1%). The <10 m fleet is likely to be the most impacted by-catch decreases in the short term (2020–50), whereas the effects will be experienced more strongly by the >10 m fleet by the end of the century in all countries. Overall, losses in revenue are estimated to range between 1 and 21% in the short term (2020–50) with England and Scotland being the most negatively impacted in absolute terms, and Wales and North Ireland in relative terms. Losses in total employment (fisheries and associated industries) may reach approximately 3–20% during 2020–50 with the >10 m fleet and associated industries bearing the majority of the losses.

Previous studies highlight the winners and losers in fisheries under climate change based on shifts in biomass, species composition and potential catches. Understanding how climate change is likely to alter the fisheries revenues of maritime countries is a crucial next step towards the development of effective socio-economic policy and food sustainability strategies to mitigate and adapt to climate change. Particularly, fish prices and cross-oceans connections through distant water fishing operations may largely modify the projected climate change impacts on fisheries revenues. However, these factors have not formally been considered in global studies. Here, using climate-living marine resources simulation models, we show that global fisheries revenues could drop by 35% more than the projected decrease in catches by the 2050 s under high CO2 emission scenarios. Regionally, the projected increases in fish catch in high latitudes may not translate into increases in revenues because of the increasing dominance of low value fish, and the decrease in catches by these countries’ vessels operating in more severely impacted distant waters. Also, we find that developing countries with high fisheries dependency are negatively impacted. Our results suggest the need to conduct full-fledged economic analyses of the potential economic effects of climate change on global marine fisheries.

The effects of climate change on marine ecosystems are accelerating. Identifying and protecting areas of the ocean where conditions are most stable may provide another tool for adaptation to climate change. To date, research on potential marine climate refugia has focused on tropical systems, particularly coral reefs. We examined a northeast Pacific temperate region – Canada’s Pacific – to identify areas where physical conditions are stable or changing slowly. We analyzed the rate and consistency of change for climatic variables where recent historical data were available for the whole region, which included sea surface temperature, sea surface height, and chlorophyll a. We found that some regions have been relatively stable with respect to these variables. In discussions with experts in the oceanography of this region, we identified general characteristics that may limit exposure to climate change. We used climate models for sea surface temperature and sea surface height to assess projected future changes. Climate projections indicate that large or moderate changes will occur throughout virtually the entire area and that small changes will occur in only limited portions of the coast. Combining past and future areas of stability in all three examined variables to identify potential climate refugia indicates that only 0.27% of the study region may be insulated from current and projected future change. A greater proportion of the study region (11%) was stable in two of the three variables. Some of these areas overlap with oceanographic features that are thought to limit climate change exposure. This approach allowed for an assessment of potential climate refugia that could also have applications in other regions and systems, but revealed that there are unlikely to be many areas unaffected by climate change.

Source: http://www.cbc.ca/news/canada/north/beaufort-sea-environmental-assessment-1.3490983

The Inuvialuit are pitching a far-reaching scientific and traditional knowledge study that would help researchers better understand how Arctic ecosystems will be affected by climate change, increased shipping and oil and gas development.

"We see ourselves as part of the ecosystem, so anything that is going to affect that is going to affect us as well," said Duane Smith, chair and CEO of the Inuvialuit Regional Corporation.

... The letter, co-authored by the Inuvialuit Game Council, says the Arctic Ocean, compared to Canada's other coastlines, is the least studied. It also calls for long-term monitoring and reports considerable gaps when it comes to understanding issues such as the amount of fish and their food sources.

UBC Institute for the Oceans and Fisheries researcher Rashid Sumaila said he thinks the Beaufort Sea would be appropriate for a broad study such as an RSEA.

"There's a lot of changes coming. This makes the place really special," said Sumaila.

On March 10, 2016 Canada and the US released a major bilateral announcement on the Arctic to coincide with Prime Minister Trudeau’s visit to Washington. The announcement includes an initiative to re-examine new conservation goals for the Arctic and a commitment to engage all Arctic nations in the development of a pan-Arctic marine protection area network. Read more about the announcement.

Climate change is expected to impact Arctic marine mammals, as they may be particularly vulnerable to large annual variability in the environment. Beluga whales (Delphinapterus leucas) occupy the circumpolar Arctic year-round, and seasonal movement patterns in this landscape are closely linked to sea ice and changing conditions. Here, we examine the association between beluga spring locations along the Mackenzie Shelf and three relevant habitat variables: sea ice (total concentration, floe size, and distance to ice edge), bathymetry and turbidity. Beluga locations in 2012 and 2013 were analyzed across the study area, as well as in three discrete subareas of the Mackenzie Shelf: Shallow Bay, Kugmallit Bay and Tuktoyaktuk Peninsula. In both years, beluga were found more than expected by chance in locations of open water/light ice concentrations and medium ice floes, and displayed a significant association with turbid water (i.e., increased freshwater flow). Largely ice-free conditions in 2012 led to a wide variation in habitat use in all three subareas. Beluga whales in 2012 preferred the ice edge and were found in heavier ice concentrations, larger floes and high turbidity water in the Shallow Bay subarea. Open water environments were preferred by beluga found in the Kugmallit Bay subarea. In contrast, heavy ice conditions in 2013 resulted in restricted habitat use and selection of shallow depth (<50 m) and low levels of turbidity. These results provide knowledge on spring habitat selection as well as insight into the adaptability of beluga under expected changes associated with climate and human activity in the Beaufort Sea.

The _Fifth Assessment Report of the Intergovernmental Panel on Climate Change_highlights that climate change and ocean acidification are challenging the sustainable management of living marine resources (LMRs). Formal and systematic treatment of uncertainty in existing LMR projections, however, is lacking. We synthesize knowledge of how to address different sources of uncertainty by drawing from climate model intercomparison efforts. We suggest an ensemble of available models and projections, informed by observations, as a starting point to quantify uncertainties. Such an ensemble must be paired with analysis of the dominant uncertainties over different spatial scales, time horizons, and metrics. We use two examples: (i) global and regional projections of Sea Surface Temperature and (ii) projection of changes in potential catch of sablefish (Anoplopoma fimbria) in the 21st century, to illustrate this ensemble model approach to explore different types of uncertainties. Further effort should prioritize understanding dominant, undersampled dimensions of uncertainty, as well as the strategic collection of observations to quantify, and ultimately reduce, uncertainties. Our proposed framework will improve our understanding of future changes in LMR and the resulting risk of impacts to ecosystems and the societies under changing ocean conditions.

Studies have demonstrated ways in which climate-related shifts in the distributions and relative abundances of marine species are expected to alter the dynamics and catch potential of global fisheries. While these studies assess impacts on large-scale commercial fisheries, few efforts have been made to quantitatively project impacts on small-scale subsistence and commercial fisheries that are economically, socially and culturally important to many coastal communities. This study uses a dynamic bioclimate envelope model to project scenarios of climate-related changes in the relative abundance, distribution and richness of 98 exploited marine fishes and invertebrates of commercial and cultural importance to First Nations in coastal British Columbia, Canada. Declines in abundance are projected for most of the sampled species under both the lower (Representative Concentration Pathway [RCP] 2.6) and higher (RCP 8.5) emission scenarios (-15.0% to -20.8%, respectively), with poleward range shifts occurring at a median rate of 10.3 to 18.0 km decade-1 by 2050 relative to 2000. While a cumulative decline in catch potential is projected coastwide (-4.5 to -10.7%), estimates suggest a strong positive correlation between the change in relative catch potential and latitude, with First Nations’ territories along the northern and central coasts of British Columbia likely to experience less severe declines than those to the south. Furthermore, a strong negative correlation is projected between latitude and the number of species exhibiting declining abundance. These trends are shown to be robust to alternative species distribution models. This study concludes by discussing corresponding management challenges that are likely to be encountered under climate change, and by highlighting the value of joint-management frameworks and traditional fisheries management approaches that could aid in offsetting impacts and developing site-specific mitigation and adaptation strategies derived from local fishers’ knowledge.