Climate Change Effects and Adaptation Approaches for Marine and Coastal Ecosystems

• Patricia Tillmann
• Dec 02, 2011

With the growing number of scientific papers on climate change and continued interest among resource managers and conservationists to account for climate change in their work, there is a need to summarize climate change information for key geographies and ecosystems. In response to this need, National Wildlife Federation produced an extensive compilation of climate change effects and adaptation approaches specific to the marine and coastal ecosystems of the North Pacific Landscape Conservation Cooperative (NPLCC) geography.

With approximately 38,200 miles of coastline, the NPLCC region extends from Kenai Peninsula in southcentral Alaska to Bodega Bay in northern California and stretches up to 150 miles inland to the crests of the Cascade Mountain Range and Coast Mountains. It is home to iconic salmon and orca, a thriving fish and shellfish industry, and a wide range of habitats crucial for the survival of many other species and for sustaining the Way of Life for many Tribes, First Nations, and Native Alaskans. Many of these species, habitats, and ecosystems are already experiencing the effects of a changing climate.

Key Findings:

• The development and survival of the tiny creatures salmon and other fish feed upon is hampered when ocean water grows more acidified. These conditions have already been observed in the southern NPLCC region and are projected to continue in the future.
• Sea level rise, increased extreme wave heights, and more intense storms are projected to increase beach and bluff erosion and lead to shoreline retreat, loss of coastal habitat, and damage to coastal infrastructure. However, in some areas such as southern Alaska, sea level may remain relatively stable or decline, limiting overall habitat loss.
• Warmer waters are likely to promote increased populations of Pacific salmon in Alaska while stressing populations elsewhere in the region. Rising sea surface temperatures also contribute to sea level rise and increased storm intensity.
• Coastal areas with enhanced river inputs, such as the Columbia River estuary, may experience harmful algal blooms and hypoxic (low-oxygen) waters.
• Aleutian Tern, Kittlitz’s murrelet, beach-nesting black oystercatchers, Cassin’s auklet, and other sea and shorebirds are vulnerable to climate change-related loss of habitat and food sources. In 2005, complete nesting failure by Cassin’s auklet and widespread deaths of other seabirds (common murres, sooty shearwaters) was linked to a delay in plankton production off the Pacific Northwest coast (from the normal April-May to August), which in turn was associated with a later start to seasonal upwelling. It is unclear how climate change may affect upwelling in the NPLCC region; some studies project more intense upwelling while others project less intense upwelling over time.
• Invasive and non-native species found in the NPLCC region such as Spartina and New Zealand mudsnail appear to benefit from climate change. Spartina, a coastal cordgrass, may colonize new areas as sea levels rise. New Zealand mudsnail, a small snail found in brackish and fresh water, may move northward due to its wide range of temperature and salinity tolerance.
• Although uncertainty and gaps in knowledge exist, sufficient scientific information is available to plan for and address climate change impacts now.

Since climate change scenarios generally project a further increase in the atmospheric carbon dioxide (CO₂) concentration and an associated exacerbation of climate change effects, adaptation is emerging as an appropriate response to the unavoidable impacts of climate change. Adaptive actions such as incorporating climate projections into land use planning, enhancing sediment transport, and supporting ecological buffer zones expected to persist over time can reduce a system‘s vulnerability and increase its capacity to be resilient to changing conditions. Ultimately, successful climate change adaptation will enhance the ability of natural and human communities to prepare for, accommodate, or cope with current and future climatic changes.