Fisheries Science Lecture Notes

MSCI 487 - R. Young, Coastal Carolina University

What is a fishery?

• Your book likes Miller and Johnson's (1981) definition as "a union of aquatic organisms and humans"
• I like my own: "a consumptive harvest of wild aquatic resources"
• Consumed for food and for industry (fish meal, animal feed, fertilizer, oil…)
• Not just fish -- various shellfish and crustaceans, squid, marine mammals, turtles…
• Though related, a fishery is not aquaculture (although hatchery-based fisheries blur the line)

3 basic elements of a fishery:

1. the resource itself
2. the aquatic environment
3. people (fishermen, seafood companies, even the broader scope of everyone who influences the habitat)

Conservation and management

• Your book defines fisheries conservation as the "wise, sustainable use of wild (naturally produced) fisheries resources."
• Much of fisheries management is simply conservation, but active management occurs in fisheries such as those supplemented by hatcheries (i.e. managed and enhanced, not just conserved wisely)

Ancient History

• 2300 BC - government fishing fleets in Sumaria near Persian Gulf
• 2000 BC - aquaculture in China for carp and other freshwater fish
• 1400 BC - Egyptian elite were fishing for recreation (vs. food)

• Worldwide fisheries harvest seems to have reached a plateau in the last 2 decades at around 85-90 million metric tons (mmt)
• Increased over 4 times since 1950 (from 18.5 million tons in 1950) (Greenpeace)
• Another 25 mmt or more each year is thrown back as bycatch--most won't survive (Greenpeace)
• Since 1970, the world's fishing fleet expanded twice as fast as the world catch (Greenpeace)
• overcapacity means pressure to exploit
• as a whole, the world fishing fleet has been operating at a multi-billion dollar deficit each year through much of the 1990's (Greenpeace)
• Worldwide, about 13 million people make all or a major part of their living from fishing (Greenpeace)
• Combined with their immediate families, about 50 million people are directly dependent of fishing (Greenpeace)
• Another 150 million people are employed on land, processing fish and servicing fleets as part of their jobs (Greenpeace)
• In the U.S., about 300,000 people are employed in coastal-related fisheries alone
• The average U.S. citizen eats 16 pounds of fish/shellfish per year
• For two thirds of the world's population, fish make up about 40% of their protein consumed (Greenpeace)
• Although the amount of fish consumed be people each year has increased with the world catch, the proportion of the catch going to people has decreased (roughly 25-30% goes to fish meal for livestock, etc…) (Greenpeace)
• Recreational fishing is not to be overlooked:
• In 1990, 36 million people age 16 and over went fishing
• The money they spent supported the equivalent of 600,000 full-time jobs in fishing related industries

• What is parental care?
• Includes any combination of post-spawning care of eggs and/or larvae
• Includes other reproductive specializations which increase survival, including internal fertilization, direct nourishment of eggs, etc…
• Parental care and fecundity generally inversely related
• Types:
• Broadcast spawning (minimal care)
• Ocean spawners - usually pelagic eggs
• Freshwater/estuarine spawners - usually demersal eggs
• Egg scatterers
• Lay demersal eggs on specific substrates, but don't modify them (build nests)
• Exs. - sand lance on cont. shelf sand and winter flounder on estuarine sand, walleye over gravel/boulder, Atlantic silversides on intertidal filamentous algae mats (keep moist and hidden)
• Shelter spawners
• Many species lay demersal eggs in crevices, nooks, etc
• Some lay eggs on live inverts (sea ravens and sculpins on sponges, etc.)
• Nest builders
• Many in gravel (good aeration and protection) - lamprey, salmon and trout (redds), fallfish (see picture in book)
• Depressions in sediment - sunfishes, freshwater bass
• On vegetative material - damselfish and garibaldi (algal matt), sticklebacks construct tubular nests of fragments of vegetation
• Guarding
• Many nest builders then guard (damselfish)
• Why benefit males more? (attract more mates?) - your book takes this view only
• Or is it females that benefit? (less energy for parental care--more for egg production?)
• There are also alternative "cheating" strategies for subordinate males
• Brooding
• Internal (ovoviviparous and viviparous elasmobranchs, guppies, etc.- carry eggs inside until hatch/born)
• External - carry fertilized eggs or larvae outside of female's reproductive tract (pouches, mouths, gills, etc..)

• Estimate a daily egg and larval death rate of 2-10% for typical broadcast spawners
• 90-99% rainbow smelt eggs die before hatching
• 70-85% American shad larvae die 4-9 days after hatching
• daily mortality rate of newly hatched capelin larvae may exceed 50%
• Winter flounder and striped bass larvae have 1.2 and 1.5% average daily death rate
• Contrast with 90% survival of brown trout eggs in redds to hatching (3 month incubation period)
• Further contrast with 5-10% annual mortality rates for juveniles and adults of typical large-bodied species (generally higher for small-bodied species)
• Causes of mortality:
• Environmental causes (give examples - effect growth rates, settlement location, food availability)
• Water temperature
• Ocean currents or river flow
• Wind/waves (waves needed to free capelin larvae from sand/pebble substrate
• River discharge (affects salinity, nutrient input, plankton productivity)
• Water levels (effect amount of quality shallow spawning habitat - walleye)
• Biological causes
• Predation - by whom?
• Copepods, chaetognaths, jellies
• Small fishes (sometimes turn the table: high bluegill dnesities cause high mortality of largemouth bass eggs and larvae)
• cannibalism
• size-dependent predation (outgrow predators)
• complex interactions (predation may restrict useable space and foraging time, leading to increased competition, slower growth, and longer vulnerability to predation
• "critical period" after yolk sac absorption (typically lose weight first)
• must eat during this period
• controversy about its importance
• plankton patch hypothesis
• must exploit high density patches to be successful - may include a big random component
• planktonic larvae are likely to be concentrated by currents into areas of patches for the same reasons
• Overwintering issues
• Temperate fish usually timed to be reaching a critical size for survival by winter
• If anything slows growth (environmental or biological reasons), can have significant year-class mortality

• Fish grow their whole lives and rates are highly variable
• Changes with life stage
• Grow most rapidly early in life (exponential curve, initially)
• Growth slows at sexual maturity (energy into gametes, which are lost eventually, unlike body mass: gonadal vs. somatic growth)
• Exponential growth curve "breaks" to form a sigmoid curve
• Growth curve nearly plateaus when older (larger maintenance cost, more into reproduction)
• Variation within species
• Fast and slow growing fishes
• Fast- may reach sexual maturity earlier, but ultimate size is less (often shooting for critical size by a specific season)
• Slow-reach sexual maturity later, but grow more (longer time without emphasizing gonadal growth)
• Male/female differences
• Often, females mature later ("deferred maturity")
• larger size=more eggs
• Males of some species have deferred maturity
• Typically when males have nests or territories and larger size =more mating events (somewhat mammalian)
• Environmental factors on growth
• Temperatue and salinity have direct effects on metabolism
• Temperature, salinity, rainfall/run-off, etc. effect primary production
• Changes in water levels for freshwater fishes
• Random encounters of patches -- some fish get big advantage early on simply by chance
• Density-dependence
• Refers to intra-specific competition
• A wide variety of results and opinions
• Abundance will affect growth ONLY IF resources are limiting
• Limitation fluctuates with fish population size and with carrying capacity (neither stay constant)
• Often exploited populations are held at a reduced population size
• Density-dependent growth most obvious in years of very high abundance or years of depleted carrying capacity

• Does size matter? -- yes, probably more than age
• Age of maturity varies with growth rate (as described above), but often the critical size is the same regardless
• Especially for larger, longer-lived species (many smaller fish mature after 1 or 2 years, anyway)
• In some cases, size of maturity can decrease as well
• Compensatory reaction to fishing:
• Growth rate increases and age of maturity decreases (how does this happen?)
• ex. Herring growth rate increased 25% and age of maturity decreased by 2 years with a growing fishery (Murphy, 1977)
• Age of maturity and mortality
• Evolutionary pressures
• If likely to die early, better mature early and hope to reproduce at least once
• Ex. Scup: 80% juvenile mortality rate, reproduce at age 2
• If juvenile mortality risk isn't so bad, but reproductive risk is big, better grow large first to get the most out of that reproductive event
• Ex. Atlantic sturgeon (mature at 28 years old), spiny dogfish (mature at 12 years old or more), salmon--be anadromous to grow large
• Age of maturity versus lifetime offspring production
• Early maturity at a smaller size may offset late maturity at a large size by providing more lifetime spawning seasons
• This balance tips the other way the longer larger fish live (high fecundity for large fish)
• Mix of successful strategies varies by species and by situation
• Ex. - slow-growing Atlantic salmon may mature after 1 year at sea, but fast-growing salmon mature after 2-3 years
• Seems backwards, but predation risk for slow-growers in the ocean is high--so reproduce early

• How often and how many times do you spawn?
• Iteroparity versus semelparity
• Strategies for maximum lifetime fecundity
• Depends on number of offspring per spawning event and likelihood of survival for future spawnings
• Survival and future spawning requires:
• Survival from predation during spawning
• Recovery from physiological stress of reproduction
• Weakened, vulnerable to infection, disease, predation
• New gonadal growth
• Stress can be high enough to go years in between spawning
• Shortnose sturgeon may go 8 years
• Atlantic salmon with long freshwater migrations may skip a year, but those with short river migrations spawn every year
• If you don't have to worry about this, can put more into one reproductive event
• American shad example:
• All anadramous, coastal migrators as adults
• Southern spawners are semelparous, northern spawners are iteroparous usually
• Florida fish mature at younger age and smaller size than New Brunswick fish
• Florida fish produce 3 times as many eggs as do first time spawners in New Brunswick (and on average, twice as many eggs in a lifetime)
• Florida fish use 70-80% of energy reserves to spawn versus 40-60% for New Brunswick fish
• Semelparous fish have a greater average number of offspring per female than iteroparous New Brunswick fish (lifetime totals)
• Then why be iteroparous at all?
• Greater variability in spawning rivers in north (temperature especially) means some years might have poor survival -- better to spread risk across years

Recruitment and Management

• Recruitment is the addition of new individuals through reproduction and growth
• Used differently depending on context
• Recruitment to spawning population
• Recruitment to the fishery (the harvestable population)
• Recruitment to a reef or substrate
• Larval recruitment of demersal species (i.e. "settlement")
• Fisheries have often failed to match removal rates with recruitment, often for complex reasons
• Lake sturgeon in Great Lakes
• High fecundity, so high recruitment, right? No
• Late maturity (20 years)
• Non-annual spawning (can go years between events)
• Protogynous groupers
• Hermaphrodites - start as females, large adults become males (opposite of and more common than protandrous hermaphrodites)
• Sex ratio skewed toward significantly more females
• Large and spatio-termporally predictable spawning aggregations susceptible to heavy fishing pressure
• Fisheries target large fish (more males removed
• If males removed early enough, largest females will change sex
• Leaves fewer females for that year
• Leaves smaller females that year (less fecund)
• If males removed too late, largest females will start to change sex, but won't complete process in time
• Same problem as above, plus fewer males as well (double whammy)
• Does specific protection against recruitment overfishing help? (i.e. protect them completely until they have spawned)
• Striped bass - huge success with this strategy
• With failing stocks in the 1980's, protected 1 good year class for most of the decade until they could spawn (commercial moratorium, increasing size and number limits for recreational fishing up to 36 inches)
• Year class spawned, had a successful year class of its own, and stocks came roaring back
• BUT, it doesn't always work that way
• A big spawning event during a bad year won't help
• The striped bass strategy could have failed in conditions prevented another good year class for several years
• What if fishing pressure is completely removed? Will everything return to normal?
• Maybe not
• George's Bank groundfish
• Traditional important groundfish have been overfished (cod, haddock, pollack, various flounder)
• Replaced in late 80's and 90's with mainly spiny dogfish and skates (with their slow fecundity, this pattern took a while to develop)
• These elasmobranchs are now major predators of juvenile groundfish
• Will they prevent the recovery of groundfish populations?
• Larger questions:
• Should we expect "equilibrium" in fish community structure?
• Most ecologists would argue for a non-equilibrium system these days.
• Are there multiple stable points?
• Is it just chaos?

What types of fishery models are used to predict changes in stocks with fishing?

•   Stock Recruitment Models
• Relate size of spawning stock to expected rate of recruitment to the spawning stock (i.e. how well does the size of the spawning stock predict recruitment?)
• 2 primary models (see figures in book)
• Ricker Model - assumes density-dependent decrease in recruitment as spawning stock size increases
• Recruitment peaks at some mid-level abundance, then declines due to increased competition, cannibalism, etc.)
• In reality, stocks can only get so far along the post-peak decline before it becomes self-regulating
• You could see this kind of response, though, for stocks which significantly overshoot their carrying capacity and have a strong compensatory reaction (a decline or oscillation back below K)
• Beverton and Holt Model - assumes continual but slowing increase (toward a max asymptote) in recruitment as spawning stock size increases
• What you might expect for a stock that gradually approaches it's carrying capacity
• Typically, neither model is all that effective in predicting recruitment from spawning stock size
• Correlation is often poor
• Recruitment success often controlled more by environmental factors
• Surplus Production Models
• These are basically extensions of the Logistic equation (Verhulst-Pearl)

• N = population size in number of individuals
• T = time, usually in years
• K = carrying capacity (or max population)
• R = intrinsic rate of population growth (or the potential growth rate when unrestricted by K)
• (often, the (K-N)/K term is written as 1-N/K, but I think that obscures the obvious role of that term in the equation, in that the closer N gets to K, the slower
• the rate of population increase becomes)

• After integration and algebraic manipulation, an alternative form of the logistic equation is:

• Even a simple equation like this can lead to chaotic results (see web links to chaos sites from the discussion questions page)
• Chaos is when seemingly random and unpredictable (non-linear) patterns are derived from predictable first principles
• Slight changes in the initial parameters lead to disproportionately large differences in results with iterative models
• The figure below demonstrates several similarly shaped curves that are slightly different in meaning.
• In figure below, the derived equation above for N_(t) (above) determines the position along curve "a", while the former equation (for dN/dt) describes the curve "d" below it. Often, however, you will see the later equation given along with curve "a" (because it is the more intuitive equation combined with the more intuitive figure).

• F = instantaneous rate of fishing mortality (from 0=no fishing, to 1=all fish removed)
• Nt = number of fishes of age t
• Wt = average weight of fishes of age t
• For ages between tc (age of first capture or when 1st vulnerable to fishery) and tl (maximum age in fishery)

• Notice that Y = F*N*W for each age category, or in other words the yield (or surplus biomass) = rate of fishing mortality x stock biomass
• Add it up separately for each age class and you've got the total change in yield over time
• For a YPR model, you need estimates for:
• Natural mortality rate (i.e. without fishing) and population size
• Used to determine the number of individuals in each age class (Nt)
• Growth relationships, including age-length and length-weight relationships
• Used to determine the average weight for each age class (Wt)
• Information on the "selectivity" of the fishing gear
• Used to determine the max and min sizes, and therefore ages, captured in the fishery: (tc and tl).
• YPR models assume that natural mortality and growth parameters are independent of the level of fishing mortality, F (i.e. they are constant)
• Some extensions/modifications of yield-per-recruit models do allow examination of recruitment overfishing:
• Spawning stock biomass per recruit models (SSB/R)
• Examine effect of age of first capture and rate of fishing mortality (as before) on reproductive potential of population
• Spawning stock biomass = number of fishes at each age x proportion that are mature at each age x average weight at each age (just adding a proportion that are mature factor to the original formula)
• SSB/R will decrease as fishing mortality (F) increases
• When is it too much (i.e. when does recruitment overfishing occur?)
• Often we don’t know the stock-recruitment relationship, or it is unpredictable
• Managers have some general "rules of thumb" based more on experience with overfished stocks than with any scientific explanation
• Fishing mortality should not reduce the SSB to less than 30% of it’s unexploited level (below that, tend to get rapid declines and recruitment overfishing)
• Fishing mortality rates should not exceed natural mortality rates
• Often these 2 cut-offs are pretty close to one another
• As before, low levels of fishing mortality applied at young ages can have same effect as high mortality applied at older age
• Eggs per recruit models (EPR)
• Examines effort of age of first capture and rate of fishing mortality (as before) on maximum lifetime fecundity of the average female
• Must add a factor to original formula that determines proportion that are female and average fecundity for each age or weight class
• Increasing fishing mortality has greatest effect on species with
• Late age of maturity, or
• Large difference between age of 1st capture and age of maturity
• Cohort Models
• Calculate declining abundance of year classes as they age through a fishery
• Ex. Virtual Population Analysis
• Uses estimates of natural mortality, fishing mortality for oldest age taken in most recent year, and annual catch statistics for each age
• This is more predictive for each cohort than yield-per-recruit models
• Develops estimates of annual fishing mortality for each age, and estimates total stock abundance
• All models have limitations and assumptions!
• Beverton and Holt yield-per-recruit model: assumes fishing mortality is equal for all ages vulnerable to capture
• Surplus production models: assumes catchability does not change with fishing effort (ignores changes in vessels, gear, methods, or clustering of fish)
• Virtual Population Analysis: instantaneous rate of fishing mortality for oldest age group is not easy to nail down
• Catch data can be confusing for mixed commercial and recreational fisheries
• Etc.

Who is responsible for fisheries resources?

• Fisheries resources are "public property" (unless entirely on privately owned habitats)
• Government generally assumes responsibility for their management, paid for by:
• your tax money, and
• special fees and taxes for user groups (fishing licenses, boat taxes, etc…)

3 categories of fisheries resource users: subsistence, recreational, and commercial harvesters

• Subsistence users
• Contrary to popular opinion, subsistence does not mean primitive (although it can be)
• Subsistence users are common worldwide, but not in the US, right?
• Many people in US with low disposable income obtain much of their food from hunting and/or fishing—technically, that’s subsistence
• Recreational users (of fishing, not drugs!)
• Popularity has increased greatly in this century with increases in leisure time and disposable income
• In 1991, more than 36 million anglers fished a total of 511 million days in the US
• 85% of this effort was in fresh water
• No such thing as a typical angler
• Some are happy with any catch, others just to be on the water, others with lots of fish, others with only trophy fish
• Surveys of more frequent anglers indicate they place greater evidence on the really good catches (trophy fish, rare fish, etc.) and on experiencing time outdoors with family or friends
• Less frequent anglers are mostly interested in catching some fish
• The growth of recreational fishing has slowed in the US in the 1980s and 90s
• Less fishing licenses means less money for management
• Compensating by raising license fees may further decrease numbers – catch 22
• But, do you want everyone out fishing?
• Difficult to manage – a dispersed and unorganized group (although some segments are highly organized and effective)
• Commercial users
• Who are commercial fishermen?
• Hard working, dedicated individuals
• The money is often moderate to poor, so many do it because they love it (outdoors, independent, proud)
• Strong component of community tradition and family business
• Often a strong ethnic and cultural component, by port
• Often, each port has its own set of unwritten rules and territorial traditions
• Most are independent (not working for a large parent company, except some large fisheries, like tuna fleet)
• Problems of overfishing
• Why doesn’t everyone just cooperate?
• "Tragedy of the Commons"
• as long as someone doesn’t cooperate, it doesn’t pay anyone to cooperate
• overcaptalization
• too committed financially by the time fish stock problems become apparent
• financially forced to pursue short term success over long term success
• initially, price goes up as landings go down (supply and demand)
• encourages continued fishing as fish stocks drop
• but eventually stocks will get too low to support fishery
• regulations (catch restrictions) are often imposed just when things are getting the worst for fishermen (catches are down, CPUE is up, and suddenly they are told to catch even less—ouch!)
• government will often subsidize rather than face a total economic collapse
• but subsidies to continue to overfish are not much of a solution, either
• Why not limit entry into the fishery before overcapitalization occurs? Why allow any fishery to grow so fast?
• Often, a new fishery doesn’t come onto the radar screen of regulators until late in the game
• Fishermen don’t have to ask permission to explore a new fishery on an unregulated species
• If it is profitable, fishermen will respond much faster than scientific studies and legislation

Who contributes more to the economy, commercial or recreational fisheries?

• Tough to compare
• Commercial
• In 1993, $3.5 billion in commercial landings
• But this is just the value paid to the fishermen
• Multiply this by the income to shipyards, supply stores, repair facilities, processors, shippers, marketers, retailers, etc.
• Intense economic inpact on port communities, more distributed impact nationwide
• Recreational
• No single value of landings available like for commercial fisheries
• 1991: estimated multiple impact of $24 billion spent for marinas, gas, food, hotels, guides, boat operators, baitshops, equipment retailers, etc. (about 75% for freshwater fishing)
• a more distributed impact, generally, than commercial fishing
• although can have big impact on some local and regional tourism/recreation-based economies

 Management and allocation conflicts

• Within commercial fisheries
• Multiple fisheries within the same habitat or region often have conflicting management goals
• One fishery's bycatch may be the other fishery's target
• Within recreational fisheries
• Anglers will often comply if they understand the conservation value, but not if they think regulations favor one user group over another
• Between commercial and recreational fisheries
• Traditionally, recreational fisheries have ruled in freshwaters and commercial has ruled in saltwater
• Recreational getting more recognition in salt water now
• Recreational harvesters outnumber commercial, 300 to 1 -- tough odds for public opinion and legislation if you're a commercial fisher
• Between native Americans and other users
• Treaty agreements often conflict with regulations on other user groups
• With endangered species regulations
• Managing for one species often conflicts with managing for another species or for an ecosystem
• With water and land use practices
• With conservation groups or the public interest

Since all students in this course have had extensive coursework in general oceanography, I won't dwell on the various physical conditions that impact the aquatic habitat.

Harvesting Methods (consult pictures in your text)

• Hook and Line Gear
• Hooks - single, trebble, circle, barbed vs. barbless
• Bait - live bait, cut bait, lures, chumming
• Longlines
• Also trotlines or setlines
• Baited hooks and gangions on mainlines
• Usually set on bottom or near surface
• Spacing of gangions and materials for lines (ropes, monofilament, wire…) effects capture
• Tunas, sharks, billfish, halibut, others…
• Active hook and line
• Pole-fishing, hand lines, power reels
• Drop fishing vs. trolling (not trawling!!)
• Active Entrapment Gear
• Trawls
• Bottom, midwater, and surface trawls
• Lead or chain line on bottom (sometimes with rollers or bobbins), float or cork line on top
• Some sort of spreader (otter doors vs. beam trawl)
• Codend
• Effective capture, but often with high bycatch (can partially control with mesh size) and benthic habitat destruction
• Dredges
• Rigid framed gear
• Dig in or drag and disturb the bottom, usually to dislodge or scoop up bivalves (oyster and scallop dredge)
• Seines
• Long rectangular nets (much longer than deep), again with leadline and floatline
• Beach or haul seines
• For shallow water, set and hauled by boat or by hand
• Purse seines
• Large deepwater nets
• Set in a circle, then pull purse line to form a bowl, then haul in catch
• Good for oceanic schooling fishes (menhaden, tuna…)
• Passive Entrapment Gear
• Trap nets
• Long barriers of netting (leads or wings) extend typically from the shoreline angling toward an entrapment net
• Entrapment area is typically a series of connected funnels (some sort of fyke or hoop net)
• Use to capture fish that move along the shoreline
• Pound nets
• A slightly more permanent trap net
• Wings and sometimes entrapment area set with semi-permenent stakes
• Weirs
• Even more permanent version of trap net.
• Wings are woven walls of brush, or sometimes actual solid walls of rocks or concrete
• Trap nets, pound nets, and weirs are very effective against coastal migratory species -- restricted in many areas
• Pots and traps
• Usually pots catch invertebrates (lobster, crab) and traps catch fish
• Soak time of nets and traps effects performance
• Entanglement Gear
• Gill nets
• Size selective - smaller fish pass through mesh, larger fish can't get head in to be gilled
• Trammel nets
• Entangle fish, but don't gill them
• 2 small mesh panels on either side of central large mesh panel
• fish pushes smaller mesh through large mesh, catching itself in a pouch
• not very size selective, but useful for catch and release with minimal damage
• How do you find the fish? - advances in technology
• Fish finder sonar
• Hydrophones
• Spotter planes and helicopters
• Satellite images of thermal fronts and plankton blooms

• Freshwater resources
• Riverine
• Coldwater streams
• Defined by latitude or elevation
• Dominated by Salmonids (trouts) in terms of target fishery resources
• Warmwater streams
• Few of the headwater fish are fished for
• In mid-sized and larger rivers, fish for Centrarchids (smallmouth and then largemouth bass, sunfishes), pike, muskie, pickerel, various catfish, sturgeon…
• Lakes and reservoirs
• Coldwaters - Salmonids mostly
• Coolwaters - Pike, muskie, walleye, striped bass (introduced), yellow perch, as well as some salmonids and centrarchids
• Warmwaters - centrachids and catfishes mainly
• Anadromous and catadromous fisheries
• Salmon
• Pacific - huge fishery, it has its problems (we'll cover this more later)
• $540 million harvest for Alaska in 1990
• Atlantic - depleted, almost none in US, all Canadian (or Norwegian)
• striped bass
• east coast migratory stock, spawns mainly in Chesapeake Bay and Hudson River
• remarkable comeback in the late 80's and 90's
• introduced to west coast and San Francisco Bay
• sturgeon
• fished for roe
• largest North American freshwater fish (white sturgeon on west coast, over 1000 pounds; Atlantic sturgeon nearly 1000 pounds)
• severely depleted (less so for some smaller species) due to late age of maturity and intermittent spawning
• American Shad, alewife, blueback herring - east coast (all Clupeids)
• Catadromous American eel (small fishery here, larger fishery for similar species in Europe and Japan)
• Marine Fisheries
• Northeast/Mid-Atlantic
• Groundfish
• $161 million in commercial groundfish landings in 1992 in Northeast
• Gadids - cod, haddock, pollock, hake
• Flatfish - winter, summer, yellowtail flounder and others
• With overfishing, has been replaced by dogfish and skates
• Nearshore fishes - bluefish, tautog
• Shellfish - lobsters, scallops, clams
• lobsters and scallops are 2 most valuable fisheries in northeast, near $150 million each
• Southeast and Gulf of Mexico
• Reef fishes (groupers and snappers, mostly), caught on rod and reel or longline
• Drums (Sciaenidae - red drum, seatrout, spot, croaker, black drum, weakfish…), mostly recreational
• Menhaden
• huge purse seine fishery, especially in Gulf of Mexico
• Mostly goes to fishmeal, oil, etc.
• Nearshore warmwater fishes - tarpon, bonefish, snook
• Shellfish - shrimp, oysters (overfished), bluecrabs (overfished)
• Shrimp in Gulf of Mexico is a more valuable fishery than any other single Atlantic species (fish or shellfish)
• Atlantic highly migratory Pelagic fisheries
• Tuna, Billfishes, Sharks - much concern about these species
• West coast
• Groundfish
• Flatfish (halibut, sole)
• Rockfish
• Various Gadids (pollacks, cods, hakes)
• Walley pollock - largest single species catch in US (NOAA 1993), around 1.3 million metric tons from Alaskan shelf
• salmon
• Anchovy and sardines (large purse-seine fisheries)
• Pacific pelagic fisheries
• Similar to Atlantic, except large purse-seine fishery for tuna
• Shellfish - crabs (King crabs, dungeness), several types of clams/abalones/etc.

• Fisheries are a public resource, and governments manage fisheries for the public
• Regulations have changed a lot in the last hundred years
• Used to legislate each regulation, now legislation charges an agency with management responsibility
• Allows much faster and more practical response times
• Allows decisions to be made by people in the fishing industry (scientists, fishermen) instead of legislators
• Opens up agencies to potential lawsuits for failing to fulfill their legal obligation
• For a while in the mid-20^th century, regulations were out of fashion--they were not thought to do any good (declining stocks brought the regulation philosophy back in line, though)
• Has moved from single species regulations to multi-species regulations to ecosystem management (sort of)
• Decisions have become more cooperative, with Fishery Management Councils including researchers, fishers, and the public
• Origins of management
• 1639 - Mass Bay Colony prohibited use of striped bass and cod as fertilizer
• striped bass revenues were taxed to support colony's first public school and provide aid to widows and children
• numerous other colonies passed fishing regulations in 1600's and 1700's (catch limits, restricted seasons, gear restrictions) -- it all sounds familiar!
• Creation of fisheries agencies
• Several states formed fisheries agencies in the mid-1800's (depletion of many anadromous fishes, problems with dams, etc.)
• US Fish Commission
• Established in 1871 in Woods Hole
• First federal conservation organization of any kind!
• Spencer Fullerton Baird was first commissioner and basically lobbied for and created it
• Main concern was depletion of New Englands fish populations (especially cod)
• Baird determined it was the fault of the bluefish -- dumb conclusion or a logical product of its time?
• Fish Commission established a marine science tradition at Woods Hole
• Attracted top scientists, like Alexander Agissez
• Established marine biological laboratory
• Henry Bigelow's work on the Gulf of Maine, including extensive fish surveys, lead to his being the first director of Woods Hole in the early 1920's
• Fish Commission went through many iterations and name changes, but eventually it became what we know of today as the National Marine Fisheries Service (NMFS) or NOAA Fisheries
• Interesting struggles between commercial and recreational interests, and freshwater and marine fisheries interests
• At beginning of 20^th century, it was under the Commerce Dept. and included freshwater fisheries also
• Moved into Dept of Interior
• Commercial fisheries felt shortchanged under environmental emphasis of Dept. of Interior
• Eventually, split into commercial and sport fishery components within Interior
• In 1970, commercial fisheries are moved to NMFS under the newly created NOAA, back under the Dept. of Commerce (commercial fishing is a business), and US Fish and Wildlife remained under the Dept. of Interior to deal with freshwater fisheries (conservation)
• Interesting difference in the underlying philosophy of these 2 fisheries agencies.
• NMFS - research tradition since Woods Hole beginnings, with goal of sustainable commercial fisheries
• USFWS - management of primarily recreational sport fisheries
• Of course, there are a number of confusing areas of overlap with coastal and anadromous species
• Early regulations of the 20^th century
• International agreements (IWC, others) and interstate agreements (Atlantic States Marine Fisheries Commission) met with limited success
• Good, in that they lead to cooperative planning and discussion
• Bad, in that they had no teeth and anyone could decide to go their own way
• International Convention for Northwest Atlantic Fisheries (ICNAF)
• International agreement for the management of primarily George's Bank resources
• Foreign distant water fleet was more effective that local US or Canadian fleet
• Regulations were not preventing overfishing and collapse of resources
• Frustrated US fishermen essentially turned their backs on ICNAF as an effective body
• From this discontent, the Magnuson Act was born
• Magnuson Fishery Conservation and Management Act (1976)
• Extended federal territorial waters to 200 miles
• Promoted conservation action to aid recovery of depleted stocks
• Established a system for fishery management plans (FMP's) developed by regional management councils (including scientists, fishermen, managers)
• Goal was to manage for optimum yield (OY) rather than maximum sustainable yield (MSY)
• Some fall-out from Magnuson Act
• Hague Line - division between US and Canadian water on George's Bank (US lost some prime fishing grounds)
• American Fisheries Promotion Act
• In absence of foreign fleet, Congress passed this act to fund fisheries expansion and development (more boats, facilities…)
• This occurred before stock recovery
• Lead to fishery boom in early 80's and horrible crash in late 80's and 90's
• Reauthorization of Magnuson Act (late 90's)
• Includes emphasis on habitat and ecosystem management as well as species management
• Returns focus to MSY (and OY can be addressed, but should be based on MSY foundation)
• Places more emphasis on bycatch reduction
• Reduces rampant conflicts of interest in regulatory decisions
• Puts narrow time windows on management decisions
• Atlantic Coastal Fisheries Cooperative Management Act (1993)
• Extension of earlier Striped Bass Act which successfully rescued striper stocks
• Effective interstate agreement, because it has teeth
• An individual state can choose to disagree and disregard a widely agreed upon regulation
• This decision is reviewed by the Secretary of Commerce
• If secretary disagrees with the state's choice, they must comply or face a fishing moratorium
• Other regulation issues
• Treaty fishing rights of Native Americans
• Most prevalent in Pacific Northwest (salmon)
• Treaty rights often conflict with management decisions
• In cases of dispute, where tribes have a claim to the harvest of managed species, the tribes typically receive 50% of the allowable harvest
• Technically, they are a sovereign nation, with a 50% claim.
• Federal courts have normally based treaty-right rulings on the premise that:
• Treaties must be interpreted as the tribes understood them at the time of signing, and
• Ambiguous points are generally resolved in favor of the tribes
• Endangered species
• Some of the first acts to save "insignificant" species were for fish (native species, dessert pupfish, etc. in the 1950's and 60's
• Endangered Species Act of 1973
• Powerful, because there were to be no exceptions -- if a species is endangered, it must be protected, regardless
• The snail darter and the Tellico Dam (mid 70's)
• 1^st big test - protect a "useless" fish by stopping a major TVA dam project
• prompted amendments to ESA in 1978, to include economic considerations in decision
• dam was still rejected on these grounds, but they went around it with a legislative exemption from Congress.
• Lead to further strengthening of ESA legislation again in the 80s.
• Marine mammals (they were a fishery, too)
• In 1972, the Marine Mammal Protection Act eliminated all marine mammal fisheries in the US, and protected all marine mammals and prevented trade in marine mammals
• If marine mammal stocks were managed wisely, such that extinction was not such an imminent risk, would anit-whaling sentiments have caught on so strongly? Interesting thought.

• Size limits
• More easily done with recreational fishing than with commercial fishing
• Although, mesh size can do this to some degree for commercial fishing, especially for gill nets and traps, and somewhat for trawls
• But larger mesh may also encourage additional fishing effort to still get the same size catch -- leading to recruitment overfishing of larger fish and greater effort and expense by the fishermen--not good
• Minimum size limits
• Usual goal is to protect spawning potential, but this regulation may have other goals as well:
• Increase biomass production by waiting longer to harvest
• Increase catch of larger individuals or create trophy fisheries
• Increase predation levels on forage species (ex. Larger bass keep bluegill stocks down, leading to larger individual bluegill)
• Slot limits
• Catch fish within the slot, but not smaller or larger
• Too many small fish would be growth overfishing
• Allowing larger fish to survive contributes to population fecundity (larger long-lived fecund fish)
• Release fish within the slot size range, but keep smaller or larger fish
• For fish with consistently high juvenile recruitment
• Removal of small fish leads to density dependent growth increase (plus, many small fish aren't kept by anglers anyway)
• Reproduction occurs for fish within the protected slot limits
• Large fish still available for trophies and generally satisfactory fishing trips
• Strategy fails if no one keeps the small fish (will not lead to faster growth rates and increased catches of large fish) -- but at least this failure does not lead to fishery collapse
• Compliance with size limits
• Compliance is often poor
• Sometimes >50% noncompliance -- many of which are not close enough to be honest mistakes
• Anglers will make mistakes even when they know they will be inspected (do all anglers exaggerate?)
• Even so, it's better than nothing
• Catch and release mortality
• Depends on species, water temp, gear, bait, experience of angler, etc.
• Can be as high as 88% for bluegill caught on worms (live bait more likely to lead to gut-hooking)
• Can be extremely low
• 0 % for walleye caught on lures
• 0.3% per capture, with the average fish caught 10 times/year for Yellowstone River cutthroat trout
• Catch Limits (or creel limits, named after creel baskets)
• Recreational catch limits
• Widely used, often in conjunction with size limits
• Can sometimes backfire
• Anglers may regard limit as a target and actually keep more than they normally would if unsure about stock condition
• If catch and release mortality is high, it does little good
• Catch-and-release only
• This is supported in areas where the draw is more than just fishing
• Beautiful natural areas, unusual species or particularly large fish
• Commercial Annual Quotas
• Would be impossible to enforce for recreational fisheries
• Can put hardships on commercial fishers
• Exhausting "race" mentality to the fishing season
• Difficult budgeting -- make all your money in a short period
• Big difficulties with bycatch issues
• If quota is reached for species A, what do you do if it continues to be captured as bycatch in the fishery for species B?
• You could shut down the fishery for B, also -- not a popular choice
• You could allow the B fishery to continue fishing, but they must throw back all A that are caught -- doesn't help much, since A probably dead when thrown back
• You could estimate the amount of bycatch expected and subtract that from the target quota, so you shut down the fishery for A at a lower number, and the A that continue to be caught as bycatch are still thrown back, but they have been built into the quota already -- this is not a pretty solution either, but it seems to be the lesser of the evils
• Closures
• Limited seasons, and specific closed times for the season are accepted by most fishermen as necessary and intelligent
• This becomes more of a hot button issue if closures get longer due to overfishing, or if the entire fishery is shut down

• Regulating fishing effort
• Limited entry fisheries and Individual Transferable Quotas
• Individual quotas for each boat eliminates "race mentality" hardships of fishery-wide annual quotas
• As stocks increase, fishers resent having their harvest restricted
• Also, this may not manage stocks well if more boats can just enter the fishery
• Can limit catch by limiting the number of boats
• Must grandfather in any boats fishing at the time the regulation is enacted
• If fishery improves, there is much social and political pressure to let more boats in
• But usually, the concern is at the start of the regulation, when a fishery is crashing and everyone is overcapitalized
• Transferable quotas allow a fisher to get out of the business and still make some money by selling their quota to another boat who is staying in the business
• This is often coupled with a government buyback program of boats, as well
• Pacific halibut longline story
• Early 1990's, Canada met it's quota by establishing individual vessel quotas, but the US simply limited the halibut season to a short period (in at least one year, it was only a single day!) because they had too many boats to keep track of individual quotas
• Canadian vessels got more for catch, because landing were spread out over year and price stayed high, so the US moved to individual quotas as well, despite the logistical difficulty
• Gear Restrictions
• Commercial harvest - depending of species and situation, certain gears are deemed too efficient and are not allowed
• Recreation fishing
• Hook restrictions (circle vs. single vs. treble) can target mortality rates
• Fly-fishing only restrictions target certain stocks and streams for the "unique experience" -- they're often catch and release only streams, too
• Bycatch Restrictions
• Shrimping
• The worst bycatch offender - Discard biomass can be 18 times greater than shrimp harvest in Gulf of Mexico!
• BRD's (bycatch reduction devices)
• TED's (turtle excluder devices)