Complexity and Simplicity in Fishery Management

By Barry Darby (November 2020)

There is a general sense that the management of our ocean resources is a difficult and complex task. Media stories, DFO assessments and conflicting reports from harvesters, producers and pundits further highlight that view. Certainly much of the science involved can seem contradictory and confusing – ocean warming, climate change, plankton, egg-to-biomass ratios, forage fish, seal predation and so many other factors.

In the midst of all this complexity, however, it’s easy to miss an aspect of fishery management that is relatively simple – the harvesting plan. Whether planning the harvest of a single species or using a more integrated ecosystem approach, it’s a matter of translating the scientific knowledge into actual practice. The purpose is to ensure that fish harvesters know what they can and cannot do.

Perhaps surprisingly, the harvesting plan itself can be quite simple – a set of straightforward rules that answer the following four questions:

• Who can fish commercially?
• What gear can they use (eg. hook and line, traps or pots, nets, trawls)?
• Where can they fish (fishing zones or areas)?
• When do the seasons open and close?

However, that is not the way DFO does harvest planning. For almost all our fisheries, the Department’s plans are based primarily on a fifth question: “How much fish should be caught?” But answering that fifth question is immensely more complicated than answering the first four.

The current system, Quota-Based Management (QBM), attempts to quantify allowable catches and use the resulting quotas to plan the harvest. However, this approach introduces complexities and contradictions which actually interfere with sustainable fishery management.

Under QBM, managers combine data from previous landings and estimates from studies and sampling, then use them to produce stock assessments, define numerical reference points and make projections. Although this approach tries to take into account the many diverse and ever-changing variables inherent in the ocean’s ecology, it is simply impossible to do so with the level of accuracy required to plan for sustainable harvesting.

Moreover, by making pre-defined maximum catch numbers the deciding factor in harvest planning, QBM prevents us from responding appropriately and in real time to the reality of the fish stock. For example, if the existing stock is in poor condition due to low food supply, catching more of them can actually help the remaining fish survive, so they can thrive and replenish the stock into the future. A quota that artificially limits the catch does the opposite.  

What is needed is a management system that can identify and respond to what is actually happening in the water. In fact, such a system – effort-based management (EBM) – is used successfully in one of our most important fisheries. For over 90 years, our lobster fishery has been remarkably successful in economic, ecological and social terms – something we should be seeking to achieve for all our harvested species. And it is managed without quotas (output controls), relying instead on regulating fishing effort (input controls.)  

EBM makes harvest planning relatively simple. Instead of making the allowable catch and the quotas derived from them the overriding priority, managers focus on the practical tools for ensuring a harvest that maximizes both sustainability and net economic returns. Real-time data and the latest scientific research are used to define answers to the first four questions: who can fish, how can they fish, where can they fish and when can they fish? Those answers constitute the harvesting plan in each case.

In a few fisheries, there may be reasons to use some output controls such as trip limits or even seasonal limits, especially during a period of transition to EBM. But the principal way we would regulate harvesting would be by controlling effort.

As explained in my proposal, Changing Course – A New Direction for Canadian Fisheries, there would be many advantages to using effort instead of quotas as the management basis for most species. Stocks would be more sustainable: regulating effort to curtail the harvest of large, fecund fish would minimize damage to the stock’s reproductive capacity. Harvests would be optimized, averting both overfishing and underfishing, and minimizing bycatch. Quality would improve and higher landed value would result. Better rules known well in advance would benefit both harvesters and processors.

No management system can be perfect, but some systems are better than others. Managing by effort will make harvest planning both simpler and more effective than the current system of quotas, and the result will a more sustainable fishery overall.