Bering Sea Marine Invasives

We investigated the potential risk of non-native species to the Bering Sea through a ranking system developed to assess species’ traits, environmental suitability, and shipping traffic. We created habitat models relating species’ physiological tolerances gathered from literature to current and future climate scenarios to map areas of current and future concern. Last, we analysed shipping traffic from commercial and fishing vessels to identify ports of entry for invasive species.

At present, there are relatively few non-native species in the Bering Sea. However, it is predicted that Arctic regions – including the Bering Sea – will become more susceptible to invasions because of changes in climate and shipping traffic^4,5. Given the importance of the Bering Sea to Alaskans, and the current lack of knowledge, evaluating the potential threat of non-native species in the region is needed to help inform management, monitoring, and research priorities.

Species Ranking

Our ranking system evaluates the potential threat of non-native taxa to the Bering Sea. Each species is evaluated and scored independently following an in-depth literature review. Overall scores can range from 0 (least threat) to 100 (highest threat). The system contains 33 questions grouped into 5 categories. A score is calculated for each question based on the response selected. The ranking system can account for missing data by calculating the final score based only on known answers. We evaluated a total of 46 taxa that occur in the Bering Sea and nearby marine ecoregions.

Nearest Occurrence	Taxonomic Group	Scientific Name	Common Name	Rank Score	Status Report	Spatial Data
0- Bering Sea	Fishes	Alosa sapidissima	American shad	49.25
1W- Oyashio Current	Crustaceans - Barnacles	Amphibalanus amphitrite	Striped barnacle	57.5
1E- Gulf of Alaska	Crustaceans - Barnacles	Amphibalanus improvisus	Bay barnacle	65.21
2E- Alaskan Panhandle / British Columbia	Mollusks - Gastropods	Batillaria attramentaria	Asian horn snail	46
1E- Gulf of Alaska	Tunicates	Botrylloides violaceus	Chain tunicate	56.25
2E- Alaskan Panhandle / British Columbia	Tunicates	Botryllus schlosseri	Golden star tunicate	57.95
2E- Alaskan Panhandle / British Columbia	Bryozoans	Bugula neritina	Brown bryozoan	62.63
0- Bering Sea	Crustaceans - Amphipod	Caprella mutica	Japanese skeleton shrimp	64.95
2E- Alaskan Panhandle / British Columbia	Crustaceans - Crabs	Carcinus maenas	European green crab	69.5
2E- Alaskan Panhandle / British Columbia	Tunicates	Ciona savignyi	N/A	52.25
3E- Vancouver, Washington, Oregon	Cnidarians - Hydrozoan	Cordylophora caspia	N/A	46.84
1E- Gulf of Alaska	Mollusks - Bivalves	Crassostrea gigas	Pacific oyster	74.25
3E- Vancouver, Washington, Oregon & 3W- Sea of Japan/East Sea	Mollusks - Gastropods	Crepidula onyx	Onyx slippersnail	46.84
3E- Vancouver, Washington, Oregon	Cnidarians - Anthozoans	Diadumene lineata	Orange-striped green anemone	50.13
2E- Alaskan Panhandle / British Columbia	Tunicates	Didemnum vexillum	Carpet sea squirt	65.64
3E- Vancouver, Washington, Oregon	Tunicates	Diplosoma listerianum	Compound sea squirt	52.75
2E- Alaskan Panhandle / British Columbia	Cnidarians - Hydrozoan	Ectopleura crocea	Pink-mouthed hydroid	54.47
3E- Vancouver, Washington, Oregon	Crustaceans - Crabs	Eriocheir sinensis	Chinese mitten crab	51.75
3E- Vancouver, Washington, Oregon	Crustaceans - Ostracods	Eusarsiella zostericola	N/A	33.91
3E- Vancouver, Washington, Oregon	Annelid - Polychaete	Hediste diadroma	N/A	38.83
1W- Oyashio Current	Crustaceans - Amphipod	Jassa marmorata	N/A	57.18
3E- Vancouver, Washington, Oregon	Crustaceans - Copepods	Limnoithona tetraspina	N/A	34.26
3E- Vancouver, Washington, Oregon	Crustaceans - Isopods	Limnoria tripunctata	N/A	50
3E- Vancouver, Washington, Oregon	Mollusks - Bivalves	Macoma petalum	Atlantic macoma	46.75
3E- Vancouver, Washington, Oregon	Crustaceans - Amphipod	Melita nitida	N/A	47.3
1E- Gulf of Alaska	Tunicates	Molgula citrina	N/A	53.15
2E- Alaskan Panhandle / British Columbia	Tunicates	Molgula manhattensis	N/A	45
0- Bering Sea	Mollusks - Bivalves	Mya arenaria	Soft-shell clam	59.5
3E- Vancouver, Washington, Oregon & 3W- Sea of Japan/East Sea	Crustaceans - Copepods	Mytilicola orientalis	Red worm	36.12		N/A
1W- Oyashio Current	Mollusks - Bivalves	Mytilus galloprovincialis	Mediterranean mussel	67.75
3E- Vancouver, Washington, Oregon	Cnidarians - Anthozoans	Nematostella vectensis	Starlet sea anemone	43.47
3E- Vancouver, Washington, Oregon & 3W- Sea of Japan/East Sea	Crustaceans - Shrimp	Palaemon macrodactylus	Oriental shrimp	49.87
3E- Vancouver, Washington, Oregon	Crustaceans - Amphipod	Paracorophium spp.	N/A	29.15		N/A
3E- Vancouver, Washington, Oregon	Mollusks - Bivalves	Petricolaria pholadiformis	False Angelwing	44.11
3E- Vancouver, Washington, Oregon	Mollusks - Gastropods	Philine auriformis	New Zealand sea slug	49.71		N/A
3E- Vancouver, Washington, Oregon & 3W- Sea of Japan/East Sea	Annelid - Polychaete	Polydora cornuta	Whip mudworm	51.25
3E- Vancouver, Washington, Oregon	Annelid - Polychaete	Pseudopolydora cf. kempi	N/A	47.4		N/A
0- Bering Sea	Fishes	Salmo salar	Atlantic salmon	49.25
1E- Gulf of Alaska	Bryozoans	Schizoporella spp.	Orange ripple bryozoan	51.78
1W- Oyashio Current	Crustaceans - Tanaids	Sinelobus cf. stanfordi	N/A	50.42
1W- Oyashio Current	Tunicates	Styela clava	Clubbed tunicate	55.25
3E- Vancouver, Washington, Oregon	Crustaceans - Isopods	Synidotea laticauda	N/A	39.45
2E- Alaskan Panhandle / British Columbia	Mollusks - Bivalves	Teredo navalis	Naval shipworm	54
3E- Vancouver, Washington, Oregon	Mollusks - Gastropods	Tritia (Ilyanassa) obsoleta	Eastern mudsnail	46.41
1W- Oyashio Current	Mollusks - Bivalves	Venerupis philippinarum	Japanese littleneck clam	63.24
2E- Alaskan Panhandle / British Columbia	Bryozoans	Watersipora subtorquata complex	N/A	58.51

Acknowledgments

This project was made possible through funding from The North Pacific Research Board (NPRB) and the Aleutian and Bering Sea Islands LCC (ABSI LCC) provided funding this project. We would like to thank our research partners, Tony Fishbach at USGS and Jordan Watson at NOAA. In addition, we would like to thank Tracey Gotthardt who was instrumental in the development of this project, and Casey Greenstein, Lindsey Flagstad, Catie Bursche, Jaime Weltfelt, and Curtis Whisman contributed to developing the ranking system and the species status reports. Thank you to Jennifer Dijkstra, Nora Foster, Kelly Krueger, Linda Shaw, Christina Simkanin, and Peter Westley for the time and energy they put into the expert review process. Thanks to Jen Karnak of Marine Exchange of Alaska, who assisted with vessel identification, and to Rob Bochenek and Dr. William Koeppen of Axiom Data Science for assistance in extracting the ROMS data. Additional thanks goes to Matt Carlson and Paul Schuette from the Alaska Center for Conservation Science for providing valuable feedback on the final report.