Preserve the Atlantic Salmon: No More Sushi For Me

Atlantic Salmon

Fig. 1: The top picture is a young fish before smoltification (Freshwater)

the bottom picture is a young fish post-smoltification (Saltwater migration).

Source: http://www.fda.gov/ucm/groups/fdagov-public/documents/image/

ucm223802.jpg

Blog entry by: Nathaniel M. Abrea

Family: Salmonidae

Common Name: Atlantic Salmon

Scientific Name: Salmo salar

Description

            The Salmonidae family share a few characteristics observable throughout each genus: an adipose fin on top of their bodies, and they are all commercially harvested as a food source. The differences in each genus are a result environmental factors—such as food, habitat, and native region—giving way to the development of a diverse amount of characteristics. The Atlantic Salmon, in particular, have very unique physical and biological characteristics (FDA).

Described as having an elongated silver-like body, covered in small scales, the average salmon can grow to be as big as twenty-eight to thirty inches long, and eight to twelve pounds heavy (NOAA). Male Atlantic Salmon have also been observed to develop an “exaggerated hooked lower jaw,” and “staggered teeth.” Some of these characteristics, such as the color of their scales, will change depending on if they are located in a freshwater environment or a salt water environment. These location changes will be determined by which phase they are in, in their observed life cycle (FDA). Overall, the Atlantic Salmon go through several distinct life phases starting from birth (NOAA).

Fig. 2: Fertilized salmon eggs, called "roe."
Source:http://www.fda.gov/ucm/groups/fdagov-public/documents/image/
ucm223797.jpg

Atlantic Salmon are born in gravelly areas, described as “coarse substrate,’ within streams, referred to as “natal streams”. As these fish grow up, they will feed on insect and worm larvae, shellfish, and fish eggs, including their own species, in their natal streams for an average of two to three years. Once mature enough, Atlantic Salmon will then migrate to the ocean for another two to three years before migrating back to their natal stream in the late fall. If they are female they will lay their eggs, and if they are male they will seek to fertilize eggs (NOAA & FDA). This ability to migrate back and forth from freshwater and saltwater is called being, “anadromous,” and is correlated to a physiological change called, “smoltification (NOAA).” Once fertilized, the eggs will be buried by the female, and only about nine to twenty percent will survive the winter to hatch in the spring to start their lifecycle. One characteristic that is also unique to Atlantic Salmon is their ability to sometimes live after spawning, labeled as “iteroparous.” Once the eggs have been laid and fertilized, a few salmon will survive long enough to spawn a second time (FDA).

Geography & Population

Fig. 3: A map of the migration patterns of Atlantic Salmon from multiple
origin points in North America Europe.
Source: http://bioweb.uwlax.edu/bio203/s2009/webb_laur/images/
northatlanticup-l.jpg

Historically, the Atlantic Salmon have been found as far north to parts of Greenland, and as far east to parts Europe. For the Atlantic Salmon that originate from the Maine Distinct Population Segment (DPS), they frequently travel to the waters of Northern Canada and Southern Greenland (fig. 3). According to the FDA, Atlantic Salmon are “extinct in 84% of the rivers in New England that historically supported salmon.” The “remaining 16%” were also found in “critical condition” as population counts of returning adults were low within the “eight rivers in Maine” that still provide a good habitat for Atlantic Salmon (NOAA & FDA). The NOAA also states that smolt production has been experiencing a large decline.

Listing Information

The Atlantic Salmon of the Maine DPS were listed as an endangered species on December 17, 2000. The Atlantic Salmon that were counted upon this listing included “naturally reproducing” remaining fish from the Kennebec River to the head of the St. Croix River, and also salmon in a hatchery rearing program—including their offspring. However, the salmon in a hatchery rearing program will not be counted in the case of delisting or reclassification (NOAA).

Cause of Listing

            According to the NOAA, the main reasons for listing the Maine DPS Atlantic Salmon revolved around: “vulnerability” due to low return rates, “excessive or unregulated water withdrawal,” stream water quality, diseases such as Infectious Salmon Anemia (ISA) and Salmon Swimbladder Sarcoma (SSS), predation increases, commercial fishing, and practices that “pose ecological and genetic risks.” These reasons have been correlated as outcomes to threats such as: “acidified water,” climate change, and human interventions—in regards to actions such as development and fishing.

Recovery Plan

            From the PDF document supplied by the NOAA, the beginning execution of the recovery plan will concentrate on the survival and maintenance of current populations that reside in the identified habitat rivers of the Maine DPS. Once the population decline has been hopefully reversed—or at least negated—and survival rates increased, then the next phases will proceed to address identified threats to the Atlantic Salmon. The ultimate goals of this recovery plan is to get the Maine DPS Atlantic Salmon delisted, and then fully recovered as a self-sustaining species. As a result of the complex situation, the NOAA proposes that a “stepwise approach” should be used by first concentrating on remediating the low adult returns and then to full recovery.

Objective 1: Stop the population decline and improve the probability of long-term survival rate.

The following criteria have been identified as milestones to the completion of Objective 1:

Criteria 1: Populations of Atlantic Salmon are indefinitely sustained in “at least the eight rivers” that had existing populations “at the time of listing.”

Criteria 2: “The replacement rate […] of adult salmon […] is greater than 1.0”

Once Objective 1 has been fulfilled, the following next objectives have been identified:

Objective 2: Self-sustaining populations are established.

Objective 3: Threats are mitigated and the self-sustaining populations are “viable.”

Though it has been deemed impossible to determine the total cost of the recovery plan, the NOAA have estimated that the first three years of implementation will cost approximately $36.6 million.

Personal Action

            As a citizen of the United States, a consumer, and future Landscape Architect there are a number of ways that I can take personal action to ensure that I am not negatively impacting the recovery of the Atlantic Salmon. I can assist in the lobbying of more environmental policies that will aid in the preservation of freshwater habitats and estuaries, and limit take in fisheries. As a citizen and future architect, I can aim to bring awareness of salmon recovery by adjusting my diet and limit my consumption of Atlantic Salmon to reflect my support.

Fig. 4: Atlantic salmon in the form of sushi.
Source: http://bioweb.uwlax.edu/bio203/s2009/webb_laur/images/sushi.jpg

Works Cited

 "An Overview of Atlantic Salmon, Its Natural History, Aquaculture, and Genetic Engineering." Veterinary Medicine Advisory Committee > An Overview of Atlantic Salmon, Its Natural History, Aquaculture, and Genetic Engineering. U.S. Food and Drug Administration, 20 Mar. 2015. Web. 4 Dec. 2015.<http://www.fda.gov/AdvisoryCommittees/CommitteesMeetingMaterials/

VeterinaryMedicineAdvisoryCommittee/ucm222635.htm>. 

 "Atlantic Salmon (Salmo Salar)." :: NOAA Fisheries. NOAA FIsheries, 14 May 2015. Web. 4 Dec. 2015. <http://www.fisheries.noaa.gov/pr/species/fish/atlantic-salmon.html>.

"Final Recovery Plan for the Gulf of Maine Distinct Population Segment of Atlantic Salmon (Salmo Salar)." NOAA’s National Marine Fisheries Service, 1 Nov. 2005. Web. 4 Dec. 2015. <http://www.nmfs.noaa.gov/pr/pdfs/recovery/salmon_atlantic.pdf>.