MOTIVATION: More evidence on why we should we spend time on fisheries economics

Global fisheries facts:

The status of the world's 200 most signficant fisheries leaves some to be desired. A "senescent" fishery is a fishery which is in decline. The FAO estimated in 1994 that about 35% of these major fisheries were in decline and identified an "urgent need of management action to halt the increase in fishing capacity or to rehabilitate damaged resources."

We should be concerned about overexploitation because historically, even in the US, there have been instances of severe depletion from overfishing of open-access fisheries.

Take a look at how global fisheries production and utilization has changed over the last decade, in particular the large growth in aquaculture.

Next, consider the regional data, especially the percentages, and in particular, the trade figures.

What is the US export market for seafood like? Japan is clearly the largest importer of US seafood. Regional dietary preferences differ, of course.

What are California's major commercial fisheries? Perhaps not what you would expect (entirely). I downloaded all of the federal fisheries data, by species and year, for the state of California and found the following information. The top ten individual species (often subspecies) are as follows. (If I had a lot more time, I would pool subspecies into major species for a better picture, but this will take many hours in a 5000-line spreadsheet, so it will have to wait):

Top ten species in terms of California harvest revenues (not profits):

Top ten species in terms of California weight harvested:

Top ten species in terms of California price per pound:

Why do we focus on Salmon in Environmental Economics?

"Anadromous" fish species, mostly salmonids, are a very important fisheries resource on the West Coast of North America. (OED definition: anadromous 1. Zool. Of fishes: Ascending rivers to spawn.) Salmon are of particular interest to environmental economists because of the vulnerability of this species. The fact that they migrate upstream in fresh waters to spawn (reproduce) means that it is much more exposed to habitat destruction and alteration. [Aside: Other types of ocean capture fishery species are pelagic (OED definition: pelagic a. Of or pertaining to the open or high sea, as distinguished from the shallow water near the coast; oceanic; now spec. living on or near the surface of the open sea or ocean, as distinguished from its depths.)]

The Chinook salmon, in particular, is an economically important fishery, even in California. (In Alaska, the Chinook is called the King salmon.) .

Salmonid populations are rather finely differentiated, since evolutionarily significant units (ESUs) are defined at the watershed level or below. A number of species of salmon in California are considered to be endangered or threatened. However, keep in mind that overharvesting is not the only contributing factor in salmon population declines. Habitat destruction and alteration is also to blame. E.g. logging practices that affect water temperature and flow rates in spawning areas; dams and diversion projects. The Columbia River salmon species have been particularly affected by hydropower projects.

It is relevant to consider the original extent of salmonid species, as well as the distribution of areas with one or more extinct salmonid species:

Or, we can take a closer look at extinction patterns in California. Clearly, human activity in much of California appears to have had an adverse effect on salmonid populations. There used to be salmon populations where we are, but they are mostly gone now.

Of the West Coast salmon populations that still remain, it is instructive to look at the status of their "evolutionarily signficant units" (ESUs). Three particular salmonid species appear to be having trouble:

Endangered/Threatened status of Coho salmon populations along the US West Coast:

Endangered/Threatened status of Steelhead populations along the US West Coast:

I've managed to find some data on the commercial and recreational catch rates for salmonid species on the US West Coast. Notice that in the early 1990s, things started to decline pretty seriously. Chinook seem to be recovering, perhaps, but coho are having real trouble. Keep in mind that catch rates are subject to regulation. It is rather obvious why Coho salmon do not appear as one of the "top ten" revenue-generating species in the commercial fishery in California in 1997.

Here are some data for the California Central Valley stocks of Chinook salmon. Notice that a proportion of these fish are hatchery fish, rather than completely "wild" fish. Again, the early 1990's saw numbers fall below the comfort zone for fishery managers.