Reversing the Decline in Fish Stocks

The stock of fish is declining worldwide at a rapid and accelerating pace.  In Can Catch Shares Prevent Fisheries Collapse? the authors survey fish stocks and find that individual transferable quotas (ITQs) do appear to work in stabilizing and even increasing stocks:

Although bioeconomic theory suggests that assigning secure
rights to fishermen may align incentives and lead to significantly
enhanced biological and economic performance, evidence to date has been
only case- or region-specific. By examining 11,135 global fisheries, we
found a strong link: By 2003, the fraction of ITQ-managed fisheries
that were collapsed was about half that of non-ITQ fisheries. This
result probably underestimates ITQ benefits, because most ITQ fisheries
are young.

The results of this analysis suggest that well designed catch shares
may prevent fishery collapse across diverse taxa and ecosystems.

One of the authors of the paper, Christopher Costello, is featured in the video below from Reason TV which covers the world wide decline in fish stocks, "capital stuffing," and the use of ITQs to solve the tragedy of the commons (FYI, all these concepts are discussed in Modern Principles).

The video mentions but does not investigate further the problem of fish and whales that travel long distances, making property rights more difficult to enforce–a good subject for classroom discussion. See also this 60 Minutes video on tuna.

Addendum: Catch-shares have recently (2009) been introduced in Cape Cod.  Here's a good primer on the costs, benefits and difficulties of implementation.  One interesting observation:

Doing away with season restrictions reduces 'derby' conditions, in which fishermen race out, even in dangerous weather, to catch as much as possible. It also eliminates seasonal market gluts, potentially increasing the prices fishermen can command for their catch.