By Anonymous -


Salmon - Sockeye
Ana Vela, Tyler Souza, Brayden Burns 
Five species of Pacific Salmon.
noyocenter.org

     There are five different types of Salmon; there are Chum, Pink, Sockeye, and Steelhead (2). Salmon, in general, are strong and determined fish, capable of swimming upstream to reach their spawning grounds. These fish will overcome obstacles on this upstream journey. By sheer strength, agility, and endurance, they are capable of leaping out of deep water about 3 meters into the air. This leaping will help them get over waterfalls and weirs. Females are typically much smaller than the males reaching a maximum of about 20kg and 120cm in length, while males can reach up to 36kg and 1.5m in length. The lifespan of these fish is typically between 4-6 years, although some individuals can live up to 10 years of age. (1)

     They breed in large numbers as they come together, traveling thousands of miles to reach a spawning location. During spawning (the release of eggs and sperm) the females will find a depression in gravel, called a redd, to deposit and bury her eggs in. The male spawners will then come along and fertilize the eggs. As part of their life cycle, the adult salmon die after spawning is complete. The eggs will develop in the gravel and will hatch out as an alevin. The term alevin refers to the fact that these newly spawned fish, or fry, carry their yolk sac with them for the next 2-3 months as it continues to provide food for them. After this period when the sac is fully absorbed, they will make their way out into open water. Spawning happens in fresh water which is where some fry may choose to live for about a year or so after they swim out of the spawning site. Some fry, however, may choose to continue downstream to the open waters of the sea as soon as they leave the spawning site. This decision making can vary by species of salmon and those who do go straight out to sea are called smolts. Unfortunately, with all the predation that the small fry may face, only a few out of each thousand eggs laid will survive to adulthood and be able to spawn, continuing the cycle of life. (2)

     The Sockeye is the best known of the Pacific Salmon. This type of salmon is red in color during the run and has a rich oil content, making it the most sought-after salmon. Sockeye will typically spawn in rivers that feed into lakes or in spring-fed/outlets of lake beaches. This specific type of salmon may travel up to 1,600 kilometers from sea to spawning site. Sockeye salmon fry will stay in fresh water, generally in lakes downstream from spawning site, for up to 3 years. These fish will eventually end up thousands of miles from their home stream and end up in the Pacific Ocean and the Gulf of Alaska. About 4-5 years later, these fish will return to their home spawning grounds for their turn to spawn. As they develop changes start to occur, they will turn varying shades of red brilliant scarlet and end up with a pale green head. Males develop hooked jaws and teeth. (2)


Salmon: Commercial Fishing

     Salmon are among the most commonly harvested fish in the U.S. making them not only
ecologically critical but also economically indispensable. Wild salmon fed indigenous Alaskans for
generations, now it fills the bellies of individuals around the world. In Alaska there are two main methods to harvest commercial salmon: set net, and drift net.

     The basic setup for set-net fishing is two posts on shore with two blocks and two safety lines.
Posts are about 2 yards apart and set where they will normally be above the high tide line (there are some tides were the posts are mostly submerged.) Roughly 100 fathoms out into the tidal plain, screw
Typical Set-net site, running lines not shown.
Seafoodscotland.org
anchors hold two blocks that are 30-40 yards apart. The main line is run between the posts via the blocks thus forming a trapezoid where one end nearly comes to a point. Using the safety lines to momentarily relieve tension, a tractor can be attached to the mainline. Once the safeties are removed the tractor can tighten or loosens the net. In this manner, the nets can be brought to shore when fishing is closed, and let out into the bay at the proper time.

Unlike set netters, drift boats round haul all of their catch using a large wench, which the net wraps around. As the net comes into the stern of
Typical Drift-net site
goodfishbadfish.com
the vessel, deckhands pick and sort the fish. When fishing, drift-netters unspool their net to its full extent. Buoys hold the net at the surface and the current drifts the set across schools of fish. This method brings in the greatest number of fish per set and is very popular due to its high mobility.

Alaska Government and Salmon Fishing:

     Both of these methods are highly monitored by the Alaska state government, which ensures enough fish make it to the breeding grounds upstream to sustain a healthy population. Every day government officials count the number of fish that make it past the fishermen's nets. Using this data, the state determines how long the men may fish the next day to ensure escapement is high enough.

     Bristol Bay is one of the many areas were these fishing in this manner takes place. Interestingly it has become a hot topic in the national news. The incredible bay is essential to the ecosystem and industry. In fact,
Bristol Bay looking inland near the fish counting towers.
Alaska Dpt. of Fish and Game. 


the bay supplies half of the worlds salmon and is one of the most productive ecosystems on the planet.

Much to the horror of fishermen and conservationists, Pebble Mining LLP is currently attempting to start mining in the Bristol Bay watershed. The EPA under Scott Pruitt is re-investigating the environmental impact of the mine. No final decision has been reached at this time, public hearings are still ongoing. (3) In a 2014 ruling, the EPA determined that $480 million dollars worth of salmon were harvested in 2009. The bay was deemed essential and several ecosystem’s health. Mining permits were denied. (4) In regards to the mine, Mr. Pruitt has released a statement saying Alaska's natural resources must be protected. Nevertheless, the administration has deemed the mine worthy of investigation.







Citation:




-(1) Hendry K &Cragg-Hine D (2003).Ecology of the Atlantic Salmon. Conserving Natura 2000 Rivers Ecology Series No.7.English Nature,Peterborough. http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=home.showFile&rep=file&fil=SMURF_salmon.pdf

- (2) “Salmon Ecology.” Salmon Ecology | Central Westcoast Forest Society, clayoquot.org/education/resources/salmon-ecology. http://clayoquot.org/education/resources/salmon-ecology


-(3) “Bristol Bay.” US Environmental Protection Agency, 30 Jan. 2018, 



-(4) Griffin, Drew, and Scott Bronstein. “The EPA Made a Surprise Move That Could Protect the World's Largest Salmon Fishery.” CNN, Cable News Network, 29 Jan. 2018, www.cnn.com/2018/01/27/politics/epa-alaska-salmon-fishery/index.html




Photos






Comments

Post a Comment

Popular posts from this blog

Mimicry: Being Masters of Disguise

By Anonymous -
Image
By: Cassidy Herbster, Cari Marota and Malik Mason  First to explain mimicry, it is copying another insect or inanimate object to aid in avoidance of predators and/or catching prey. There are two types of mimicry: batesian and mullerian. Batesian refers to when only the insect who is mimicking benefits while mullerian is when both the model and mimicking insect benefits. Most common way is with coloring. The colors of the bad tasting, venomous, or vicious insect is copied by a different insect to avoid being eaten by a predator, though the copy cat doesn't actually have that defense, it just appears so.  They also use coloring to blend in to catch prey or avoid being prey.  The insect being mimicked is called the model. Insects will not always only mimic other insects, but creatures such as arachnids or reptiles. Mimicry might not be for the whole lifetime of the insect. For example, the larvae of an insect could mimic a predator but grow up and not use mimicry as su...
Read more

Bear Lake Bog

By Anonymous -
Image
            A picture of a wetland bog from the Northern Hemisphere Source: https://infograph.venngage.com/p/176597/bog-biome               From lakeside dunes to old-growth white pine forests, Michigan is enriched with unique ecosystems. Although many of which have been claimed by society for agricultural and suburban means, portions of conserved land have been reserved for public recreation and admiration of wilderness. Wetland bogs are microcosms that serve as host to many unique organisms. While they used to be much more prevalent in the United States, they are still an important ecosystem in the US. This blog will expound on our class’s excursion to a bog named Bear Lake Bog.             Bear Lake Bog is located about six miles south of Au Sable campus and is found between the East Lakes and Bear Lake. We visited this bog on May 22, 2018. We broug...
Read more

Honey Bees and Colony Collapse Disorder

By -
Image
            Beginning in the winter of 2006 to 2007, beekeepers began to notice a significant decline in losses of their hives, as high as 30 to 90 percent for no apparent reason ( Kaplan, 2012 ). The population of honeybees continues to decline today. The disappearance of these honey bees is now known as the colony collapse disorder (or CCD). This is concerning because honeybees play an important role in the pollination of plants, especially for agriculture but the loss of honeybees doesn’t stop there. The honey that honeybees make has significant medicinal properties. Honey provides antioxidants, relief to colds, and when applied to scrapes or wounds, it aids the healing process with its natural antibacterial and antimicrobial properties ( Shock, 2015 ). It promotes digestion. The loss of honeybees is not only a threat to biodiversity but the health of plants and people. Colony losses of managed ...
Read more