Mapping Salmon – Wild and Farmed

pink salmon lice This week’s Science Magazine published a study by Erik Stokstad et al titled Parasites From Fish Farms Driving Wild Salmon to Extinction. Their findings were picked up by many news outlets including a story in The Washington Post and another story in The New York Times. If you eat fish, you’ve probably eaten a salmon and should pay attention here.

Basic outline: fish farms are placed in river estuaries that are used by young wild salmon where they usually gain weight and otherwise mature before heading out to the open ocean to bulk up, return, spawn, and start the life cycle over again. The researchers claim that sea lice from the farmed fish (kept in crowded net “pens”) are decimating the young salmon before they can get to the open ocean and the estimate that the wild runs, which have already suffered a sharp decline in the study area, are headed to extinction.

Maps on the jump…

This story is related to another The Washington Post covered earlier this December down in southern Chile where fish farms supply the bulk of American & Japanese consumption of salmon but are blamed for deteriorating conditions in nearby natural lakes which are used as nurseries for the farmed fish before they mature to adults and are moved into the ocean pens where they grow to harvest size.

Here are the two maps myself and Laris Karklis produced for both Post stories (Dec. 14 and Dec 1, 2007 referenced above). Discussion followed by maps.

Both maps show distribution of features in the main map with a series of locator maps that establish where the main map is around the globe. The Chile example combines the map with two charts showing trends and proportions for the numerical data. The Canada example depicts a young fish being attacked by sea lice in a photograph.

The Chile map calls out the story’s dateline location in a black pointer box. The Canada story didn’t have a dateline and emphasizes the process flow of salmon migration with black arrows that are keyed to a numbered chronology. The Canada regional locater includes Seattle in Washington state to better locate the viewer to a more familiar American context, and both locater globes feature a capital star and label for DC, where The Washington Post and many of our readers are based.

Both maps were completed in a few hours for publication in the next day’s edition of the newspaper and stand in as visual executive summaries of the full-text stories printed alongside the graphics.

pink salmon map canada

chile salmon farms

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