Date

June 5, 2014

Time

12:00 pm

Location

RW 432

Speaker: Matthew Burgess

Host: Mark Fitzpatrick html5-dom-document-internal-entity1-lt-endmark.fitzpatrick@utoronto.cahtml5-dom-document-internal-entity1-gt-end

Fisheries science faces a challenging combination of complexity and data

limitation that often leads to disconnects between theoretical research –

which seeks to capture as much complexity as possible – and empirical

research – which is constrained to the simplicity of the available data.

In this volume, I present studies aiming to reconcile theoretical and

empirical approaches to assessing the current status of fished populations

and designing management plans in two ways: i) by using concise mechanistic

theories rooted in measurable parameters to develop new predictive

assessment tools; and ii) by using ecological and economic theory to

develop insights whose applications are not data-dependent or system

specific. My research provides several important insights for assessment

and management in fisheries: 1) Combinations of biological and

socioeconomic conditions that eventually lead to extinction or overfishing

can often be empirically identified decades before high harvest rates and

large population declines occur, allowing for preventative management. 2)

Though there is concern that harvest value which rises as a harvested

species is depleted can lead to its profitable extinction, this threat most

often also requires catch-rates to be substantially robust to declining

abundance. Because range contraction often buffers population densities

against abundance declines, habitat destruction may exacerbate threats of

overharvesting. 3) Assessments based on single-species population models in

multispecies fisheries can often provide reliable estimates of sustainable

yields and harvest rates in populations with high vulnerability to

overfishing, but often significantly overestimate sustainable yields and

harvest rates in populations with lower vulnerability. However,

single-species assessment frameworks can nonetheless be used to identify

conditions leading to such bias, and estimate bounds on its magnitude. 4)

Diversification of fishing fleets often leads to fewer population collapses

in both managed and un-managed fisheries; and increases the positive impact

management can make on fishery yields and profits. The studies in this

volume provide new perspectives on theoretical-empirical synergies in

fisheries research, and maximizing the information value of fisheries data

through theoretical concision and ecological abstraction.