Fish Conservation and Management

Transcription

1 Fish Conservation and Management CONS 486 Imperiled and extinct fishes You win some, you lose some! Chapter 11 Ross

2 Topics Legislation and protection Extinctions: examples and common causes Extirpated: species/populations Endangered and threatened: species/populations Including (you guessed it ) SALMON!

3 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

4 Federal Legislative frameworks Fisheries and Oceans Canada (DFO) has legal responsibilities under several legislative frameworks, including: Oceans Act Canadian Environmental Assessment Act (CEAA) Species At Risk Act (SARA) Fisheries Act All geared toward promoting the effective management and sustainability of freshwater & marine ecosystems and biota

5 Oceans Act: Federal Legislative frameworks Relates to the exploitation, management, and conservation of marine resources Estuaries, coasts, oceans, MPAs Canadian Environmental Assessment Act: Requires federal departments to conduct environmental assessments for proposed projects where the federal government is the proponent (or funder)

6 Protection of imperiled species COSEWIC (Committee on the Status of Endangered Wildlife in Canada) Assesses risk status of wildlife in Canada SARA (Species At Risk Act) is federal legislation that can be applied following a COSEWIC endangered listing SARA requires biological information AND societal/economic info before a decision is reached Provides legal protection of wildlife and conservation of biological diversity

7 Canada s Fisheries Act Purpose: Provides the legal framework for regulating fish, fisheries and fish habitat responsible for sea, coastal and inland fisheries Authority to manage fish habitat But no control over habitats which fall under provincial jurisdiction Habitat protection provisions: 1. Fish passage 2. In-stream flow needs of fish 3. Destruction of fish by any means other than fishing 4. Destruction of fish habitat

8 Revised (Harper; Conservatives) Fisheries Act applies habitat provisions only to fish that are considered part of a fishery, support a fishery, or are socially important Recently (Trudeau, Liberals) re-revised Fisheries Act, is intended to reverse most of the Conservative s changes

9 Imperilment and extinction Human activities have lead to the extinction of > 40 species/subspecies in North America Most had restricted distributions Many more are imperiled (extirpated, endangered, threatened) Extinction hot-spots Many species from Great Lakes Overfishing, invasive species, habitat degradation Large group from American Southwest Water withdrawals, agriculture, habitat degradation

10 COSEWIC 2014 lists ~700 species as extinct, extirpated, endangered, threatened, or of special concern 388 vertebrates 94 freshwater fish (out of ~230 total resident freshwater species in Canada; ~90 spp. in B.C.) 64 marine fish 76 mammals, 85 birds, 69 herps 34 molluscs! 55 arthropods The rest are lichens, mosses, & vascular plants

11 COSEWIC 2014: Extinctions in Canada 6 freshwater species listed as extinct Deepwater cisco, Banff longnose dace, Lake Ontario kiyi, blue walleye & two Hadley Lake threespine stickleback Lake Ontario population of Atlantic Salmon Gone since 1898! Habitat destruction and over-exploitation Original strain is gone, re-introduction is not possible but other strains introduced!

12 Deepwater cisco: Extinct Overharvested in Great Lakes during early to mid 1900s using deep water gill nets Competition from invasive alewife/smelt and predation by invasive sea lamprey pushed them over the brink No refuges available Need really deep water; no areas available outside the Great Lakes Deepwater cisco (Coregonus johannae)

13 6 cisco species have declined in Great Lakes Overfishing (after sea lamprey affected lake trout populations) Bloater (Coregonus hoyi) was the only cisco species that remained fairly widespread due to small size (~37 cm) Then it became targeted by fisheries Now extirpated from Lake Ontario

14 Banff longnose dace: Extinct (1987) Tiny subspecies of Eastern longnose dace Restricted to small marsh fed by hot springs in Banff National Park Chlorine pollution Mosquitofish introduced in 1920s! Guppies and mollies also introduced Exotics reproduced year-round Out-competed the dace for food and preyed on eggs Remaining few hybridized with Eastern longnose Banff subspecies' unique genetic structure was irreversibly mixed Banff longnose dace (Rhinichthys cataractae smithi)

15 Lake Ontario Kiyi (Coregonus kiyi) Last recorded in 1964 Commercial overexploitation and predation, competition by exotics Two subspecies: Upper Great Lakes Kiyi: special concern Lake Ontario Kiyi: extinct

16 Real Blue walleye blue form of yellow walleye Blue walleye (Stizostedion vitreum glaucum): Extinct Important commercial & sport fish in Great Lakes Looks similar to blue colouration of common yellow walleye (Stizostedion vitreum vitreum) Lived in Lakes Ontario and Erie Last confirmed specimen taken from Lake Erie in 1965 Common until the 1950s when the population declined dramatically from overfishing and Pollution and eutrophication Predation from introduced rainbow smelt

17 Three-spine sticklebacks Common throughout temperate coastal marine and fresh waters in northern hemisphere Found in B.C. lakes and streams Many water bodies contain only a single stickleback species, but pairs of species have evolved independently in a few small lakes that are < years old No more than two species occur in any one lake, one has evolved to be limnetic, the other benthic Evolution seems to have occurred independently among lakes Some of the newest fish species we are aware of Benthic/littoral Limnetic/pelagic Dolph Schulter UBC

18 Three-spine stickleback pairs in B.C. Hadley Lake species pair: Extinct Known only from Hadley Lake, Lasqueti Island, B.C. Extinction due to introduced brown bullhead Enos Lake species pair: Endangered Restricted to a single, small lake on Vancouver Island Experiencing severe decline due habitat quality and invasives Species pair has collapsed into a hybrid swarm Paxton Lake species pair: Endangered Impacted by habitat loss and/or degradation At risk from exotic species Vananda Creek species pair: Endangered Impacted by habitat loss and/or degradation from human disturbance At risk from exotic species Benthic/littoral Limnetic Photo: Todd Hatfield

19 Devil s Hole Pup fish (pool fish) Many fish species from American SW are extinct Occurred in small, isolated, disconnected habitats Few refuges or recolonization areas Altered flow and temperatures from water withdrawals Devils Hole only habitat for one species of pup fish aka the pool fish! One of most isolated fish habitats in world

20 Pup fish (pool fish)

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24 Not dead yet: Miller Lake Lamprey (Lampetra minima) World s smallest lamprey (~ 10 cm) cute right? PARASITIC! Chemical treatment of Miller Lake, Oregon to remove to protect introduced trout Considered extinct in 1958 wrong! Adult lamprey collected in the Williamson River in 1992 Unidentified lamprey collected in Miller Creek, the outflow stream of Miller Lake in 1996 Later surveys reconfirmed extirpation in Miller Lake but identified several subpopulations outside Miller Lake sub-basin

25 Not Dead Yet: June sucker (Chasmistes liorus) Endemic to Utah Lake and Provo River, Utah, where it is now under protection Once considered extinct, now listed as critically endangered, < 300 fish in some yrs Result of predation on its young by introduced species (carp and walleye), pollution, drought, alteration of water flow, and loss of native vegetation Current conservation measures transplanted some to Red Butte Reservoir, and use that as brood stock to raise fish in Springville Utah fish hatchery. After the June sucker grow to a certain size, they are released into Utah Lake and the reservoir to help build the population Example of how hatcheries and reservoirs were used in a conservation sense to bring the wild lake population back from the brink.

26 Rose 2005 Fisheries

27 Common threads of imperilment HUMANS! Usually no single factor responsible Overharvest plus introduced species Habitat destruction plus introduced species Habitat size is not always the key issue E.g., pup fish vs ciscos Habitat interconnectedness is key because it influences Number of refuge habitats Extent of recolonization areas

28 Fish extirpated from Canada 3 species: Paddlefish Gravel chub One stock of striped bass (St Lawrence R) All exist still in US Striped bass are a conservation success story in U.S. Other populations still considered endangered in Canada Found in NB, NS, Atlantic Ocean

29 Paddlefish (Polyodon spathula): Extirpated Ancient species harvested for its eggs Grow to 2 m and weigh over 70 kg Paddlefish can live for at least 30 years Individuals are slow to mature (7 years!) Paddlefish live in slow-moving areas of large rivers & lakes Migrate to large, fast flowing rivers with gravel bottoms where eggs are protected and well oxygenated during development

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32 Paddlefish range in Mississippi River system Small commercial fishery still exists in some states Long time to maturity put it at risk Declines across entire range Loss of breeding habitat and over-fishing, dam construction blocking spawning sites, channelization, water drawoff, and pollution In Canada: last reported about 80 years ago in Lakes Huron and Erie

33 Gravel chub (Hybopsis x-punctata) : Extirpated Extirpated from Thames River in southwestern Ontario ~(1958): now patchily distributed in East/Central U.S. Prefers clear, moderately-flowing streams with gravel bottom Hunts for food in the hollows beneath rocks Decline due to siltation and sedimentation of Thames River from farmland runoff ~ 8 cm length

34 Striped Bass (Morone saxatilis): Extirpated (sort of) St. Lawrence estuary population disappeared by 1968 due to recreational harvest, bycatch & illegal fishing Still occur in Bay of Fundy and Gulf of St. Lawrence Populations listed as threatened Occurs naturally along the US eastern coast US populations were near extirpation due to overharvest Recovered in recent years will discuss in next lecture!

35 Fish that threatened/endangered in Canada 55 species/stocks endangered 40 threatened 19 endangered in B.C.:* 8 stickleback species & pairs, nooksack dace, speckled dace, Morrison Creek lamprey, 3 white sturgeon pops 2 eulachon populations, interior Fraser coho, Cultus sockeye, Sakinaw sockeye 6 threatened in B.C.:* Umatilla dace, Vancouver lamprey, Cultus Lake Pygmy Sculpin, Lower Fraser white sturgeon, Salish sucker, Okanagon Chinook

36 * In November 2018, COSEWIC released the results for an assessment of 16 southern BC Chinook designatable units (DUs) -13 DUs originate in the Fraser River with 7 DUs assessed as endangered, 4 threatened and 1 special concern - Southern Thompson Ocean Summer Chinook were deemed not at risk. - For the other 3 DUs outside the Fraser River, 1 DU (East Vancouver Island Stream Spring; Nanaimo River) was assessed as endangered and 2 Southern Mainland DUs were data deficient.

37 Cultus Lake pygmy sculpin Listed as threatened by COSEWIC ~5 cm long Only found in Cultus Lake, B.C.! Limited range and isolated Vulnerable to habitat changes E.g., Eutrophication and human activities Sylvia Letay, BCMOE

38 Salish sucker and Nooksack dace Salish sucker threatened (COSEWIC) Nooksack dace endangered (COSEWIC) Affected by forestry and habitat development Only occur in a few streams in southern Fraser Valley However, these species extend into Washington state Nooksack dace Salish sucker Mike Pearson Mike Pearson

39 Morrison Creek Lamprey (Lampetra richardsoni var. marifuga) is a rare form of the widely distributed Western Brook Lamprey: endangered Ranges in size between 10-15cm Lives exclusively in Morrison Creek A tributary to the Puntledge River in Courtenay BC Main threat is urban development

40 Morrison Creek Lamprey

41 Morrison Creek Lamprey

42 White Sturgeon (Acipenser transmontanus) Adults eat live and dead fish, invertebrates, plants and are truly opportunistic omnivores Adult white sturgeon can grow up to 6 m in length and weigh up to 800 kg! Matures 5-11 years 6 populations in Fraser, Nechako, and Columbia Rivers each suffering at least a 50% decline: endangered or threatened Habitat degradation and loss through dams, impoundments, channelization, pollution, illegal fishing and incidental catches

43 Columbia populations at risk of extirpation Upper Columbia River basin population ~1,000 adults

44 Cultus Lake sockeye salmon One of the three salmon populations listed as endangered (until Nov 2018 and 8 new Chinook endangered listings) Overfishing, freshwater habitat destruction are factors

45 Status of anadromous salmonids in BC/Yukon (as of 1996!) - of the 9,663 anadromous salmonid stocks, only 5,491 (57%) had reliable information AND information is clearly out of date but nothing more modern has been assembled!! -142 extinctions (2%) which is pretty low - but why? - habitat degradation, primarily through loss of connectivity (urbanization, hydropower development)

46 Lost Streams of the Lower Mainland lost streams = lost salmon populations 15-20% of all streams have disappeared You are here! lost stream endangered stream FRAP 1997

47 I m not dead yet! A population that was extinct lives again!! The Alouette Lake sockeye salmon Alouette Lake dammed in late 1920s No fish passage structure Anadromous salmonids extirpated Kokanee salmon have existed in the lake since then but no records to know if it existed in the lake prior to the dam In 2005, discovered that the kokanee stock could become anadromous Genetic work revealed that the kokanee and returning sockeye were the same stock of fish Alouette River Alouette dam & spillway BC Archives ARMS Alouette sockeye Original Alouette dam Archives ARMS BC

48 Alouette sockeye abundance & marine survival Alouette sockeye Year Smolt Abundance Marine Survival Adult Returns Estimate Estimate (%) , , , , , , , , , no data , Average 14, Alouette kokanee

49 What is role of overfishing in stock endangerment? Has caused stock depletions (depressing stocks thus making them at greater risk of extinction from other causes), and supplemental stocking (previous lecture) has put some stocks into special concern category. What about big bad forestry? Upper Adams sockeye driven to extinction by a splash dam in the early 1900s Best evidence of a forestry practice causing a stock extinction After the dam was removed there was some recolonization and transplants Enabled a new population to establish

50 End on a zinger: The Oregon Chub The First Fish Ever Taken Off The U.S. Endangered Species List! Involved working with landowners to restore key habitats, breeding and transplanting fish and altering dam releases to more closely resemble natural river flows Twenty years might seem like a long time (to get it off the endangered list). On the other hand, if you think of the 150 years of habitat modification that went on before, it is pretty darn quick." Huffington Post Feb 2014