Posts Tagged 'regional modeling'

Modelling the environmental niche space and distributions of cold-water corals and sponges in the Canadian northeast Pacific Ocean

Highlights

• We present the first comparison of realized niche space among six major, habitat-forming cold-water coral and sponge (CWCS) groups (sponge classes: Hexactinellida, Demospongiae; coral orders: Alcyonacea, Scleractinia, Antipatharia, Pennatulacea) occurring in the Northeast Pacific region of Canada (NEPC).
• The environmental gradients influencing CWCS niche space and breadth is driven by dissolved inorganic carbon, total alkalinity, and dissolved oxygen.
• Significant niche separation occurs among CWCS groups; high tolerance and marginality generally identify CWCS as specialists occurring in uncommon habitat conditions within the NEPC.
• Species distribution models developed for each CWCS group all share severely low dissolved oxygen ([O2] < 0.5 ml L−1) as a major predictor of habitat.
• Areas that are predicted to be suitable habitat for multiple CWCW groups primarily occurs primarily within 500–1400 m bottom depths on the continental slope and at offshore seamounts that have summits that reach into this depth range.

Abstract

Cold water coral and sponge communities (CWCS) are important indicators of vulnerable marine ecosystems (VMEs) and are used to delineate areas for marine conservation and fisheries management. Although the Northeast Pacific region of Canada (NEPC) is notable for having unique CWCS assemblages and is the location of >80% of Canadian seamounts, the extent of potential CWCS-defined VMEs in this region is unknown. Here, we used a diverse set of environmental data layers (n=30) representing a range of bathymetric derivatives, physicochemical variables, and water column properties to assess the primary factors influencing the niche separation and potential distributions of six habitat-forming groups of CWCS in the NEPC (sponge classes: Hexactinellida, Demospongiae; coral orders: Alcyonacea, Scleractinia, Antipatharia, Pennatulacea). The primary environmental gradients that influence niche separation among CWCS are driven by total alkalinity, dissolved inorganic carbon, and dissolved oxygen. Significant niche separation among groups indicates CWCS to be primarily specialists occurring in rare habitat conditions in the NEPC. Species distribution models (SDMs) developed for each CWCS group shared severely low dissolved oxygen levels ([O2] < 0.5 ml L−1) as a top predictor for habitat suitability in the NEPC. Niche separation is further emphasized by differences in the model-predicted areas of suitable habitat among CWCS groups. Although niches varied among taxa, the general areas of high habitat suitability for multiple CWCS groups in the NEPC occurred within the 500–1400 m bottom depth range which is strongly associated with the extensive oxygen minimum zone (OMZ) characterizing this region. As a result, the largest continuous area of potential CWCS habitat occurred along the continental slope with smaller, isolated patches also occurring at several offshore seamounts that have summits that extend into OMZ depths. Our results provide insight into the factors that influence the distributions of some of the most important habitat-forming taxa in the deep ocean and create an empirical foundation for supporting cold-water coral and sponge conservation in the NEPC.

Continue reading ‘Modelling the environmental niche space and distributions of cold-water corals and sponges in the Canadian northeast Pacific Ocean’

A climate change vulnerability framework for Corales del Rosario y San Bernardo National Natural Park, Colombia

Assessing the vulnerability of resources to the potential impacts from climate change is critical in implementing management strategies aimed at resource conservation. A conceptual framework of climate change vulnerability was developed for Corales del Rosario y San Bernardo National Natural Park (PNNCRSB), Colombia, a park designated to protect coastal and marine ecosystems. Climate change vulnerability scores were developed based on resource-specific sensitivity, exposure, and adaptive capacity to climate change factors (sea surface and air temperature, precipitation, ocean acidification, and inundation from sea level rise and extreme events). Exposure scores were based on exceedances of thresholds, or when applicable, inundation. Scores were calculated for 10 m2 grid cells every 5 yr between 2010 and 2100 under ‘optimistic’ and ‘pessimistic’ climate change scenarios. Sea turtle nesting beaches, coastal and interior lagoons, corals and bird habitat are the natural resources with the highest vulnerability scores. Among socioeconomic resources, recreational beaches and low-lying roads are among the most vulnerable. Based on the 2100 pessimistic scenario, adaptive capacity contributed the most to the vulnerability score (range: 34-55% contribution), followed by sensitivity (range: 27-41%) and exposure (range: 14-37%). Based on elevation alone, coastal and interior lagoons, mangroves and sea turtle nesting beaches in low-lying areas are among the most susceptible resources to inundation, which ranged from -0.7 to -172 m2 yr-1 and from -3.7 to -473 m2 yr-1 for the optimistic and pessimist scenarios, respectively. While this climate change vulnerability framework for PNNCRSB may aid in the prioritization of mitigation and conservation strategies within the park, an understanding of the approach, including its limitations and uncertainties, is recommended.

Continue reading ‘A climate change vulnerability framework for Corales del Rosario y San Bernardo National Natural Park, Colombia’


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