329 Biodiversity Flashcards
(188 cards)
Endangered species
facing imminent extirpation or extinction
endangered example
Blue Whale Oregon Spotted Frog Northern Leopard Frog (SARA, COSEWIC)
Extirpated species
species that no longer exist in the wild in BC, but do occur elsewhere
extirpated examples
Greater Sage-Grouse (SARA, COSEWIC)
Threatened species
likely to become endangered if limiting factors are not reversed
threatened species example
Fin Whale Coastal Giant Salamander (SARA, COSEWIC)
Vulnerable
particularly sensitive to human activities or natural events due to: restricted range, few populations, recent widespread declines, or other factors making them vulnerable to extirpation
vulnerable species example
Western Toad Sea Otter (SARA, COSEWIC)
red listed species
includes any indigenous species or subspecies that have, or are candidates for, extirpated, endangered, or threatened status in BC
Blue listed species
any indigenous species or subspecies considered to be of special concern (vulnerable) in BC
Canada Goose population on VI pre-europeans
Vancouver CG not numerous overwintered at coastal areas
CG 1920-1930s
Branta Canadensis moffitti introduced from Okanagan to Elk Lake. Introduced birds made small breeding population then increased to several hundred up coast to duncan
CG 1970s
hundreds of non-native hybrids introduced
CG now
15,000 resident CG that live here now year round, significant damage to human-modified and native landscapes
CG 1982
Little Qualicum river estuary health and productive brackish marsh, significant sedges, tufted hair grass, high above ground biomass, less than 20 records of CG
CG 1984
firt CG nesting on LQ estuary
CG mid 1990s
goose use had increased significantly, impacts to vegetation becoming evident
CG 2000s
impacts have escalated to the point of needing to be documented
CG 2005
gathering of comparative data. 24/56 marsh species significantly changed in frequency/mean cover. over 10,000m^2 changed to primarily bare substrate
detrital food web losses at LQ estuary
at least 17tonnes of above ground dry mass/year affecting higher trophic levels - apparent trophic cascade
secondary impact on LQ estuary
increased salinity due to increased aquifer drawdown from human use
LQ recovery
have to decrease current carrying capacity of geese could take decades especially due to hyper salinity, loss of organic matter, soil compaction
where are the worlds richest longline fishing grounds?
key foraging areas for seabirds! areas of upwelling, productive areas
longline fishing
a long fishing line deployed from a fishing vessel with up to 2500 hooks out at a time over many km’s