• The earliest records of non-native marine and estuarine invertebrates and algae in Alaska date to the late 1800s and early 1900s.
  • Most non-native species have been detected recently, with over 75% of first records occurring after 1990.
  • Algae, crustaceans (amphipods and crabs), and tunicates have been the groups most commonly detected.

Geography and Climate

Alaska is the United States' northernmost and largest state, residing between 51°N and 71°N with a landmass covering 570,380 square miles. It is also considered both the westernmost and easternmost state, since the Aleutian Island chain crosses the International Dateline. Alaska has nearly 47,000 miles of tidal shoreline including numerous islands and is surrounded by the North Pacific Ocean, the Bering Sea, the Chukchi Sea, and the Beaufort Sea.

Along Alaska's various coastlines, climate varies considerably with latitude, water temperatures, currents, continental geography, and sea ice extent. The southeastern and southwestern regions of Alaska (bordering the Pacific Ocean and Gulf of Alaska) experience a maritime climate, while the coastal climate transitions to subarctic and arctic from the Bering Sea up to the Chukchi and Beaufort Seas. Marine bioregions that border Alaska are NEP-I, NEP-II, NEP-III, and the Polar Arctic.

Overview

With its extensive coastline, northern latitude, and shipping patterns heavily influenced by the oil and gas industries, Alaska is a unique state in regard to marine and estuarine non-indigenous species (NIS). Although Alaska has relatively few records of NIS compared with other states on the west coast of North America, marine and estuarine NIS detections in Alaska are increasing.

Coastwise transfer of NIS from other, more heavily invaded eastern Pacific regions is a significant pathway for introductions and major human activities at risk of transferring NIS to Alaska include shipping (via both ballast water and hull fouling), aquaculture, and the live bait trade. Climate change may encourage northward spread of NIS into Alaska as increasing sea temperatures lower the barriers for NIS already established at lower latitudes. The emergence of Arctic shipping routes as sea ice recedes may also create additional pathways for NIS to become established in Alaskan waters.

Taxonomic GroupNameYearInvasion StatusPopulation StatusVectors
FishesAlosa sapidissima1893DefiniteEstablished
Crustaceans-AmphipodsAmpithoe valida1995DefiniteEstablished
TunicatesBotrylloides violaceus1999DefiniteEstablished
TunicatesBotryllus schlosseri2001DefiniteEstablished
AlgaeCampylaephora kondoi*1967DefiniteEstablished
Crustaceans-AmphipodsCaprella mutica1995DefiniteEstablished
Crustaceans-CrabsCarcinus maenas2022DefiniteEstablished
AlgaeCaulacanthus okamurae1996DefiniteEstablished
AlgaeChroodactylon ornatum*1998DefiniteEstablished
TunicatesDidemnum vexillum2010DefiniteEstablished
Cnidarians-HydrozoansEctopleura crocea2003DefiniteEstablished
AlgaeGracilaria vermiculophylla2017DefiniteEstablished
TunicatesMolgula citrina2008DefiniteEstablished
Mollusks-BivalvesMya arenaria1905DefiniteEstablished
Crustaceans-IsopodsOrthione griffenis2017DefiniteEstablished
AlgaeSargassum muticum1974DefiniteEstablished
BryozoansSchizoporella japonica1998DefiniteEstablished
AlgaeStirkia sinicola*1998DefiniteEstablished
ProtozoansTrochammina hadai*1989DefiniteEstablished
* = Species summary still under review.