Fish Conservation and Management CONS 486 Fisheries Exploitation Chapters 4 and 5 Ross
Fisheries Exploitation Fisheries sectors (i.e., user groups) Fisheries harvest methods
Major theme: Linking science to conservation & management Physiology Behaviour Population ecology Ecosystem ecology Habitat data (limnology, oceanography) Life history Basic science Applied science Fisheries exploitation data Applied life history data Human dimensions: socioeconomic data Protecting populations & habitats Restoring populations & habitats Conservation Management Harvest regulations Managing fisheries & habitats
Introduction This section of course deals with conservation issues and management approaches Have to balance fish conservation with demands: Drinking water Electricity Housing developments Industries (mining, mills, oil) So to harvest, conserve and protect fish Fisheries managers must manage people as much (or more) than fish!
What is a fishery: review Three components to a fishery: 1. Aquatic resource itself (i.e, targeted organism) 2. Aquatic environment (i.e., habitat) 3. Humans that harvest resource OR change habitat
Fisheries sectors aka user groups Users (fisher): those who capture fisheries resources Need to understand user motivation in order to manage the people portion of a fishery Fisheries sectors/user groups: 1. Recreational 2. Commercial 3. Subsistence
User groups: Recreational Recreational: Leisure activity, fish often consumed but not sold Many secondary industries: important economically for those that support the user Largely but not exclusively in freshwater systems 85% of total recreational fishing days are in freshwater systems Motivation: relaxation, competition (i.e., tournaments), protein
Recreational capture methods Hook-and-line: rod-and-reel angling or trolling
Recreational capture methods Throw nets for smelt
Recreational capture methods Spear fishing (or spear gun)
Recreational capture methods Noodling...
User groups: Commercial Commercial: business activity, fish sold for money Motivation: economic benefit, family/community activity
Commercial capture methods Hook and line gear: Longlines: series of baited hooks attached to floats Left to passively fish Trolling: active form of dragging baited or lured hooks from a boat
Commercial capture methods Active entrapment gear Trawls and dredges: bag with cod-end dragged through water column or on bottom Can be destructive to bottom fauna and can catch a lot of non-target fish Cod-end can be adapted for size-selectivity
Trawl
Commercial capture methods Seines: fine mesh curtain with a floating top and sinking bottom Littoral fishes captured in beach seines Hauled onto shore Pelagic fishes captured by purse seines Bottom pulled in creating a closed bag which is hauled to or onto vessel
Seine brailing
Seine ramping
Commercial capture methods Passive entrapment gear: Trapnets & weirs: gear is fixed in one spot Usually nearshore and fish are passively corralled into entrapment area Bycatch can be released easily Traps or pots: portable gear Set at any depth Highly efficient for crab and lobsters
Commercial capture methods Gillnets: long wall of mesh that can be set at any depth Anchored to shore, a boat, the bottom Target fish size based on mesh size Bycatch mortality can be high but can be managed Gillnets are not always efficient I.e., sockeye at spawning grounds dropouts
Gill Net Scars Amy Teffer UBC/Uvic gillnetted fish, fungus fish several days following gillnet encounter
Proportion net-marked Gillnet injuries of fish arriving at Seton River fish fence (near Lillooet BC, 350 km from ocean) Number tagged 2014-2016 averaged
Fish that can t ascend fishway and die wash back onto the fence - all had gillnet injuries
Gillnet injured sockeye at Seton River Fence (proportion of total captured) How are these fish getting injured? -mostly from downriver fisheries! 0.6 0.4 0.2 0 0 10000 20000 30000 40000 Gillnet Fishing Effort Lower Fraser River (hours per week) Adam Kanigan, MSc research
Proportion of population Migration and fitness consequences of net injury Arrived spawning grounds Migration mortality Died on spawning grounds without spawning Spawned Migration mortality 3 x higher for net marked fish Pre-spawn mortality 3 x higher for netted fish Art Bass, PhD research
Hinch lab photos Laboratory fishing simulation experiments
Commercial beach seine fisheries for salmon
User groups: Subsistence Subsistence: User consumes the resource Motivation: source of protein, cultural importance Nat Geo
Subsistence capture methods All of the above and more! Wikimedia commons
Fishwheel
Each sector can have bycatch Will discuss in subsequent lectures!
Coming up next Using life history data to help in Management, and Fisheries OVERexploitation!