Sea-Level Rise and Coasts

With increasing sea surface temperatures due to climate change, harmful algal blooms in Alaska marine waters are becoming more severe, threatening food security and public health by reducing availability and safety of shellfish and other marine food resources. Paralytic shellfish poisoning, a neurotoxin primarily produced by marine phytoplankton Alexandrium, is the most severe and...

Major floods in Southeast Alaska and Hawaiʻi that potentially threaten life, property, and culturally significant resources and ecosystems are caused by mechanisms related to intense precipitation for both locations as well as snow melt-based processes for Alaska. Small, high-gradient, and heavily vegetated watersheds with direct contribution to the ocean are common in both locations. To...

Marine shellfish are an important diet and cultural resource for many Alaskans. Harmful algal blooms can produce toxins which accumulate in shellfish and can cause disease and death in consumers. Climate change is predicted to expand the timing and strength of harmful algal blooms which may affect food security for many Alaska Native Tribes and communities. Predicting when the shellfish...

Assessments that incorporate areas from land-to-ocean, or “ridge-to-reef", are critical to examine how land-use practices are altering stream discharge and nearshore marine health and productivity. Stream systems in both Alaska and Hawaiʻi are expected to experience changes in water quality associated with changing environmental conditions and increased human-use. Watershed systems...

Coral reefs are declining worldwide due to a combination of stressors, but climate induced ocean warming is the biggest threat. Warming oceans lead to ‘coral bleaching’ and frequent death, compromising the structure and function of reefs. The increasing frequency and severity of bleaching means that human intervention is needed to support the adaptive capacity of reefs. Most proposed...

For the past few years, “king tides,” or the highest tides of the year, have been occurring more frequently and significantly affecting coastal environments across Hawaiʻi. Now, disappearing beaches and waves crashing over roadways are seemingly the “new normal.” In response, the state of Hawaiʻi is implementing adaptation strategies to combat tidal flooding in coastal areas. While flood...

Fish that migrate between fresh and salt waters, called diadromous fishes, are integral to coastal Tribal cultures as subsistence foods. Throughout their Northeast range, diadromous fish populations have shown strong declines over recent decades due to the combined impacts of habitat loss, pollution, overfishing, and climate change. These changes have led to decreasing access to...

The combined effects of climate change (e.g. increased freshwater supply, sea level rise, etc.), leveeing of the Mississippi River, and the gradual settling of soil have led to a land loss crisis in coastal Louisiana. Coastal wetlands provide various ecosystem services to local coastal communities, such as storm protection, flood control, and habitat for economically and ecologically...

Coral reef ecosystems serve as natural coastal defenses, support local island economies, and are important sources of food for coastal communities. However, an increase in coral bleaching events, and the associated declines of coral cover and diversity, are highly likely as sea surface temperatures continue to rise. Multiple coral bleaching events between 2013 and 2017 have already...

The Squaxin Island Tribe (SIT) is descended from maritime people who have lived and prospered along the shores of the southernmost inlets of the Salish Sea for millennia. Climate change is projected to result in lower low water flows, higher peak water temperatures, and bigger and more frequent floods, due to both changes in peak flows and sea level rise. These changes could have...

Madagascar, a country rich in natural capital and biodiversity but with high levels of poverty, food insecurity, and population growth, faces a number of development challenges, including obtaining sustained financial support from external sources and building internal capacity to address the poor environmental, health, and socio-economic conditions. Climate change poses an increasing...

The Northeast U.S. coast is experiencing some of the fastest rates of sea level rise in the world. The Boston Harbor Islands National Recreation Area is particularly at risk from sea level rise and coastal storm impacts. Erosion and storm impacts have already led to the degradation of shoreline habitats and protective structures (e.g., sea walls), as well as direct impacts to historic...