Category: Literature Cited

A. (n.d.). Northern Elephant Seal. Retrieved October 16, 2020, from https://www.pinnipeds.org/seal-information/species-information-pages/the-phocid-seals/northern-elephant-seal

Arctic tern. (n.d.). Retrieved October 16, 2020, from https://www.nationalgeographic.com/animals/birds/a/arctic-tern/

Arctic Tern Sounds, All About Birds, Cornell Lab of Ornithology. (n.d.). Retrieved October 16, 2020, from https://www.allaboutbirds.org/guide/Arctic_Tern/sounds

dfg.webmaster@alaska.gov. (n.d.). Home Page, Alaska Department of Fish and Game. Retrieved October 16, 2020, from https://www.adfg.alaska.gov/

Future Challenges for Salmon and the Freshwater Ecosystems of Southeast Alaska (U.S. National Park Service). (n.d.). Retrieved October 16, 2020, from https://www.nps.gov/articles/aps-17-1-6.htm

Phillips, L., Chambers, N., & Backensto, S. (n.d.). Migration: On the Move in Alaska (U.S. National Park Service). Retrieved October 16, 2020, from https://www.nps.gov/articles/aps-17-1-1.htm

The Arctic tern is often considered the champion of migration. I believe one reason people are so drawn to this event is that the arctic tern represents a mass migratory event and the ability of an animal to travel thousands of miles to reach a more habitable environment for their species to flourish. Fortunately, the arctic tern migrates to two areas of the world that are not densely populated by people. Although the overall species population is declining, this limits the harmful effects that humans could have on terns.

Arctic terns are extremely impressive since they are not considered good swimmers, however, their flight from Alaska to Antarctica is almost exclusively over water. The migration of the arctic tern is considered one of the great wonders of the natural world. If you are interested in seeing arctic terns and will not be traveling to Alaskan areas during the summer of Antarctica wintering grounds, it is possible to spot them in coastal North American during May and smaller populations breed along the North Atlantic shore in New England.

Their migration season is during summer where they will move from Alaska to Antarctica. This species of tern experiences more daylight than any other animal. Additionally, terns will begin breeding during early May in Alaska. They typically nest near fresh or salt water on sandpits, beaches, and islands. However, if they nest inland then they tend to occupy wet tundra or ponds. Female terns will lay two eggs and both sexes are responsible for incubating them in the nest. The tern eggs will hatch approximately twenty days later and will soon after embark on the 12,000 mile journey to Antarctica.

https://www.pensthorpe.com/wp-content/uploads/2020/05/Discover-Birds-game.pdf

The migration of Alaskan salmon is a remarkable migratory event that showcases the ability of one species to collectively move for reproductive purposes. In fact, recent studies have shown that salmon may use the magnetic field of the Earth to guide their migration patterns. In Alaska, there are five recognized species of salmon including pink (humpy), chinook (king), chum (dog), coho (silver), and sockeye salmon. Salmon will migrate upstream to return to their home streams and river to reproduce and ensure the survival of their offspring. As you can see from videos and pictures, the migration of salmon is unlike any other marine migration people have witnessed. The environment of Alaska is serene and it is only fitting that such a unique experience occurs in the rivers and streams there.

Few species of salmon will even travel upwards of 2000 miles to return to their spawning ground in time for the breeding season. Importantly, once a male and female salmon reproduce and the female deposits the eggs in a redd, a hole in the riverbed, then both salmon will die. The annual migration of salmon depicts perfectly the lifecycle of this fish from fertilization to death. This unique event draws thousands of Alaskan fishers and bystanders to watch the migration each year.

However, Alaskan salmon are facing more challenges than ever before. For example, in Alaska, the temperature is rising causing the average temperature of rivers to rise and become lethal to some species of salmon. In one case, salmon in the Ugashik River refused to swim upstream since the water was significantly warmer upstream. Instead, they remained in the cooler and deeper water and were never able to reproduce during the breeding season. Climate change is also becoming a pervasive issue because it is permanently affecting salmon migration patterns and river habitat. Humans are also negatively affecting salmon populations through river water diversion and straying hatchery salmon so that they do not return to the original place they were hatched. The migration of salmon is a unique display of the circle of life and is a must-see experience before it becomes irreversibly affected by climate change.

https://www.hcn.org/issues/45.20/ecosystems-101-hard-lessons-from-the-mighty-salmon-runs-of-alaskas-bristol-bay

Northern elephant seals will migrate twice a year between the Californian and Mexican beaches. They are unique in that, no other animal shows this type of biannual migratory pattern. On average, females will spend 300 days at sea while males will spend 250 days traveling.  There are only three times per year when elephant seals will be visible on the shore. This occurs during the breeding season, molting (shedding skin) season, and in the fall. Most births will take place in January only a few days after the female has arrived onshore. Northern elephants undergo a shedding of fur in sheets that occur over the course of a few months which is not visible for most other marine species. Also, northern elephant seals spend a prolonged period of time traveling in the sea so it is extremely rare to be able to see them congregate on the beaches of CA and Mexico.

Fortunately, elephant seals are not currently endangered, however, they were at one time and subsequently underwent a genetic population bottleneck. This was due to the large number of seals that were killed for blubber oil in the 19^th century. Today, the primary concerns for seals are the few that are shot and killed and collisions with boats or cars. Additionally, climate change remains a threat to many marine animals due to rising sea temperatures affecting the migration patterns and typical routines of these seals. If you see elephant seals on beaches during breeding season or molting season, be sure to keep a significant amount of distance between you and the animal. Most beaches that experience an influx of elephant seal breeding and migration will be closed during this period of time. However, they can be viewed from afar at several rookeries. This is a fantastic migratory event to experience if you live along the west coast or are traveling there between the months of December and March. It is also critical to observe these animals in their natural habitat as too often, marine animals are misused for entertainment in aquariums or theme parks. By observing elephant seals during their migratory patterns you can gain a better understanding of their lifestyle and place as simultaneous predators and prey in the ocean ecosystem.

Find out what Northern elephant seals sound like:

https://www.marinemammalcenter.org/education/marine-mammal-information/pinnipeds/northern-elephant-seal/