Lecture Slides Flashcards
How is Scope of Ecology linked to Resource management? 5
- population growth
- competition between species
- origin/maintenance of biological diversity
- influence of physical environment
- trophic webs ( = feeding webs)
Biodiversity in the Ocean?
% of marine species, benthic/pelagic
4-14% marine species
- most benthic 98%, 2 % pelagic
Phytoplankton
plants
Zooplankton
animals
Nekton
active swimmers (fish, birds, whales, sealions, etc.
Benthos
live on bottom (epifauna)
live within bottom sediments
West Wind Drift
Through April - Sept brings warmer winds, nutrients which supports BC’s coast.
- adds 10% to Oceans Primary productivity
- adds 20% to Worlds Fishery Catch
How have bottom trawlers effected the re-introduction of Sea Otters?
Bottom trawlers focusing on polluck which has a direct influence on Sea Lion populations which is impacting Killer Whale prey counts which may explain the struggle for the re-introduction of sea-otters (new source of prey for killer whales)
How many Estuaries in BC? How do they support a variety of marine resources?
442 estuaries in BC
- Support a variety of marine resources through their function as a nursery.
What is an estuary?
semi-enclosed by land, which is diluted by freshwater runoff
- freshwater input may be small or large.
What is the broad ecological importance of estuaries? 5
- Highly productive
- habitat for wildlife
- invertebrates - many species in high abundance.
- Nursurt grounds for marine fish “resources”
- migratory pathway for salmon
Dungeness reliance on estuaries?
Mass tidal migrations
- go up into estuaries to feed during particular seasons.
Juvenile Salmon reliance on Estauraries
- provide rapid growth
- partial refuge from predators
What is the potential link between inbound adult salmon and outbound juvenile salmon?
Adult Salmon die providing nutrients for Harpacticod copepods which are a major source of prey for juvenile salmon - assists growth.
Benefits of Eel Grass? 5
- refuge from predators
- enhance food resources
- reduce local current velocities
- produce oxygen
- stabilize shoreline and stores carbon.
What % of commercial fish have been supported through Eel Grass in BC?
80%
What is a current issue with marine estuaries?
- estuaries are economically/industrially attractive due to their unique situation.
- Sheltered harbours & access to rivers (transport)
- Liquid waste disposal, including sewage and industrial effluent.
May lead to:
- Habitat degredation & destruction
- Chemical contamination (pollution)
- In turn creates:
Eutrophication - algae can outcompete eelgrass - Habitat loss/destruction
Pacific Herring
- Importance?
- Foundation Species
- Dominant forage fish in BC
- Ecological importance but also economic and culturally significant.
Recruitment age?
age/size of a species that is harvested.
Pacific Herring
Where/when do they spawn?
In high biomass years, what can they reach?
Spawn December - June in a ‘silver wave’ from California - Alaska
- Discrete short lived spawn events along 450 - 600km BC coast each year.
- Can reach aggregations of 1million adult herring spawn per - ha (in high biomass years)
Link between Bears and Herring
Black Bears consume herring eggs
- similar timing between spawn and emergence from dens
State of Herring in BC
- how was the data collected?
Acheological data suggesting information on abundance, distribution and variability.
- Archaeological data came from midden deposits (areas where FN disposed of bones, shells and other food sources)
Archaeological Data?
- Shape based bone identification (family, genus, species)
- Quantification (number of identified bones, abundance is relative)
Significance of Salmon?
Salmon effect food webs across ecosystems.
Relationship between Bears, Salmon and the terrestrial environment?
Bears are direct consumers of salmon.
- Bears are primary vectors into the forest.
- Forage in daylight and darkness
- Typically consumed brain, roe and dorsal muscle
- Transfer up to 100m
- When salmon are available and abundant bears leave a large portion of carcass that is consumed by multiple scavengers.
what influences how far Bears take fish into the terrestrial environment?
How far have they been known to transfer salmon?
distance predicted by energetic reward: salmon density, fish species, sex and size, bear density and habitat.
- up to 100m
Why are Chum salmon taken into the forest more than pink by bears?
- due to their size and fat (greater energetic reward)
Other vectors of salmon into the forest?
animals?
Natural processes?
wolves, mustelids, eagles
- carcasses, urine, feces and guano
- flooding and groundwater flow.
How many vertebrates eat salmon?
39 species (8 mammals, 2 amphibians, 29 birds)
15 N? Where is it found?
How is it brought into terrestrial environment?
What can it inform us of?
- How?
Found in marine environments, salmon in particular.
- brought into terrestrial environment from migration of salmon upstream and decomposition of salmon in terrestrial environment.
- Eaten by Fly Larvae, Burying beetles and a range of other animals.
- It can inform us on historical salmon abundance through identifying amounts of 15 N in tree ring size, etc.
What are some N-rich indicators and N-poor indicators?
Identified through plants
- N- Rich: Salmonberry, Foamflower
- N - Poor: Blueberry, Red huckleberry, Salal, Deer Fern.