Tuesday, September 05, 2017

Halibut Mapping

The International Pacific Halibut Commission (IPHC) carries out annual surveys to assess halibut stocks in eleven regulatory areas, from northern California to the Bering Sea. A new interactive map has used this survey data to visualize how the numbers and size of halibut in the Pacific Ocean have drastically fallen since 1998.

Mapping change in weight, length, and abundance of Pacific Halibut: 1998 - 2015 visualizes two quantifiable facts about halibut stocks in the survey areas. The colored circular markers show both the total pounds of halibut (size of marker) and the percentage of halibut over 32 inches (color of the marker). This means that users are able to easily visualize the falling numbers of halibut and the reduction in size of the fish.

This reduction in size and numbers of Halibut in the Pacific is reinforced by the overall numbers in each survey area. If you hover over a regulatory area on the map you can view the number of halibut, the total pounds of halibut and the percentage over 32 inches for the selected year. A bar graph also dramatically highlights the shrinking numbers of halibut since 1998.

The good news is that halibut numbers in the last few years have improved in many of the regulatory survey areas, especially in those along the west coast of Canada and the USA. This is probably due, to some extent, to the conservative management of fish stocks over the last decade.

This halibut stocks map was created by Lis Fano. You can view more of her maps on her online portfolio.

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