General Outline What are fisheries?

1. Introduction • Definition: an entity representing the harvest 2. Fisheries Science animals from aquatic environments 3. Effects of Fishing • Exploitation 4. Fisheries – Economics Management – Biology – Societal Aspects a. Politics • Conservation b. Economics • Politics c. Societal Aspects • Regulation

Types of Fisheries: How to catch a fish

• Artisanal: traditional fishing effort involving • Hooks – Rod and reel households; small-scale in economic input and – Longlines effort; often associated with subsistence fishing, • Traps may be commercial in nature; usually local in • Nets effect. - Seines • Commericial: capitalization of catch with a larger- - Gill nets - Trawls scale economic input and effort; usually larger - Etc. than household group. • Projectiles • Recreational: fishing for sport – Spears – Harpoons • Alternative methods – e.g. Dyn-o-mite History of Fishing Fundamental Problems • Earliest fishing implements – bone harpoons (90,000 yrs old) from Congo (2-m long catfish) • Overcapitalization • Artisanal fishing efforts – extinction of Stellar Sea Cows (1768) • Overfishing • 1700-1900s: Whales, Seals, Otters, Turtles, Cod, Herring, • Long-term damage to marine ecosystems Haddock, etc. • Industrial Revolution and Technological Advancement • Extinction

–Steam engine –Fleet development –Refrigeration –Transportation –Navigation

Biological theory of exploitation Tragedy of the commons

Garret Hardin, Science (1968) • change of N per time t Yield Scramble competition: when • (Surplus of population) many share a resource, the population resource is at strong risk to get depleted (= species goes extinct) growth rate because the economical strategy is to get more than the others (=maximize gain). • We see this problem in hunting/ fishing but also on grazing on N=population size public land. K=Carrying capacity

Fisheries Science

• Roots in Population Ecology • Applied ecological research that provides information for management structures • Empirical Work • Modeling • The logistic growth function can be – Stock Assessments solved for Y and so we can get the surplus – Compensation/Depensation for known K and r. – Allee Effect The Models: Summarized Evolution of models reflects the evolution of our understanding of these systems •length–age •weight–length •fecundity–length • Maximum Sustainable Yield (MSY): Maximum use that a renewable •maturity–age resource can sustain without impairing its renewability through natural •spawner–recruit growth or replenishment •selectivity–age • Total Allowable Catch (TAC): Amount of catch managers allow to be taken Classical Neo-Classical EBM • - 1970s and early: logistic growth model, deterministic, no •length–age environmental or stochastic variation •weight–length Ecosystem-Based • - 1980s: depensation – low survival at low density, stochasticity in •fecundity–length Approaches early life history, maximize MSY •maturity–age • - 1990s: precautionary – use MSY as limit •spawner–recruit Hmmmm… •selectivity–age • - 2000s: ecological considerations •stochasticity •species interactions Modern •environmental interactions

Fisheries Impact: Oops…forgot about all that pesky Biology “I believe that the cod fishery, the herring fishery, the pilchard fishery, the mackerel fishery, and probably all the great sea-fisheries are inexhaustible; that is to say, nothing we can do seriously affects the number of fish (Thomas Huxley 1883)”

Peruvian Anchovy Fishery

Status of Fisheries Impact: Global Marine Fisheries Trends Oops…forgot about all that pesky Biology “I believe that the cod fishery, the herring fishery, the pilchard fishery, the mackerel fishery, and probably all the great sea-fisheries are inexhaustible; that is to say, nothing we can do seriously affects the number of fish (Thomas Huxley 1883)”

• Extinctions due to overfishing • Numerical • Ecological • By-Catch – catch of non-target species (generally discarded) • Economic Collapse • Habitat Degradation • Reduced Ecosystem stability U – underexploited D – moderately exploited M – fully exploited S – overfished R – recovering Fishing Down the Food Web Why did this happen? Food Web • Inaccurate estimates of population sizes – Models descriptive, not predictive 3.8 • Parameters inaccurate (e.g. Catch-per-unit-effort (CPUE)) 3.1 – Biology of species can drastically affect the assumptions of these models – Use of destructive fishing practices – Ignorance of ecosystem affects 2.3 • Inappropriate economic incentives 2.3 2 • Lack of political/social will

Reductions of Top-Level Predators Example: New England Groundfish and Lobsters

2004 Catch: $253.5 million 62 million lbs.

Age distributions and reproduction

photo from www.daisymaefishing.com Life History Strategies: Example: Rockfish Larval Abundances Age-structured schedules of mortality and reproduction • Long-lived: late age at first reproductive maturity • Aggregation • Low intrinisic rate of increase – offspring number • Differential reproductive value to older individuals • Strong association with specific habitat

Example: Red Hinds and Nassau Groupers in The Economic Issues Bermuda

• Scramble Competition (Tragedy of the Commons) – No advantage to helping your neighbor – No advantage to saving for later • Unlimited access • Growing demand on limited resources • Subsidies that stimulate overcapacity • Ignorance about impact Modern approaches: Despite improvements in science, lag in action and lack of Closed management cycle causes problems Access • Traditonal tools: – Gear restrictions – Regulation of Catch and effort • Access structure (limited entry into the race-to- fish): – Limited entry • Regulate number of licenses • Marine Protected Areas (MPAs) – Individual quotas (IQs) • Transferable (ITQs) • Vessel (IVQs)

Modern approaches: Decision Making Modern approaches: • “Minister of Fisheries” (United Kingdom) Spatial Scales – Ultimate authority lies with the minister • Unit Stock • Council (USA) – Fisheries can be defined into discrete independent units – Appointed individuals from various sectors; try to build – Not biological or economically accurate consensus but ruled by majority vote – Evolutionary Significant Unit (ESU): • (1) Substantially reproductively isolated from other conspecific • Commission (international) population units – Representatives from membership councils • (2) Represent an important component in the evolutionary legacy of a species • All entities beginning to adhere to precautionary • Metapopulations axioms (risk management) – population consists of interacting sub-populations – extinction/colonization – source-sink dynamics