Nearshore Marine Systems

At the interface between oceans and continents lie nearshore ecosystems, defined by well-known species with well understood ecological relations, where high densities of specialist predators (sea otters, sea ducks, black oystercatchers, sea stars) exist within a diverse and productive system full of kelps and invertebrates that don’t occur in any other habitats. This is the marine ecosystem that is most familiar to and highly valued by society. However, nearshore marine ecosystems face significant challenges at global and regional scales, with threats arising from both the adjacent lands and oceans. Monitoring composition and abundance of species and understanding functional relations in the nearshore ecosystem is essential when responding to and managing present and future threats. The legacy of knowledge provided by prior nearshore science allows us to tease apart human threats from naturally induced causes and provide guidance for management of those valued resources.

A conceptual model of terrestrial and marine interaction.
A conceptual model showing the interaction of nearshore vital signs monitored by the Southwest Alaska Network. The nearshore intertidal area is influenced by the ocean (blue arrow) and land (green arrow). Some of the main components of this nearshore system include sea birds that feed in the ocean and nest on land; sea stars and other marine macroinvertebrates in the intertidal zone; sea otters, keystone predators, that feed on sea urchins in kelp beds; and black oystercatchers that feed on mussels and other intertidal macroinvertebrates and nest in the intertidal zone. Learning about each of these components and how they interact increases our understanding of these important systems.

For an example of how ecosystems are connected, check out this video by the National Oceanic and Atmospheric Administration (NOAA)-Alaska Fisheries Science Center: 2020 Gulf of Alaska Ecosystem Status Report (video).
  • Close up of a bed of kelp.

    Kelp and Eelgrass

    Kelps and eelgrasses provide understory and ground cover for planktivorous fish, clams, and urchins.

  • A researcher prepares instruments to measure ocean characteristics in the intertidal zone.

    Marine Water Chemistry

    Marine water chemistry, including temperature and salinity, are critical to intertidal fauna and flora.

  • A researcher surveys  mussels.

    Marine Intertidal Invertebrates

    Intertidal marine invertebrates are a food source for seabirds, marine mammals, and terrestrial carnivores, such as bears.

  • A puffin floats in the ocean.

    Marine Birds

    Marine birds are top-level consumers of marine invertebrates such as mussels, clams, snails, limpets, and forage fish.

  • A Black Oystercatcher on a rocky beach.

    Black Oystercatchers

    Black Oystercatchers provide a unique opportunity to view the nearshore zone from the perspective of an avian predator.

  • A sea otter floats looking attentive.

    Sea Otters

    Sea otters can dramatically affect the structure and complexity of their environment.

Last updated: May 11, 2021