The Distribution and Diversity of
Demersal Fish Communities in the Broken Group Islands
Pacific Rim National Park Reserve of Canada Tomas Tomascik Heather Holmes
Western Canada Service Centre Pacific Rim National Park Reserve
CANADA’s NETWORK OF MPAs Environment Canada • National Wildlife & Marine Areas • Migratory Bird Sanctuaries Fisheries and Oceans Parks Canada • Marine Protected Areas • National Parks • National Marine Conservation Areas
PARKS CANADA MANDATE National Parks Act “The National Parks of Canada are hereby dedicated to the people of Canada for their benefit, education and enjoyment, …. leave them unimpaired for the enjoyment of future generations.”
NMCA Act “Marine conservation areas are established in accordance with this Act for the purpose of protecting and conserving representative marine areas and for the benefit, education and enjoyment of the people of Canada and the world.”
PARKS CANADA MANDATE National Parks Act Ecological integrity: “Maintenance of ecological integrity through the protection of natural resources shall be the first priority when considering park zoning and visitor use in a management plan.”
NMCA Act Ecological sustainability: “Marine conservation areas shall be managed and used in a sustainable manner that meets the needs of present and future generations without compromising the structure and function of the ecosystems,..”
RATIONALE FOR THE STUDY • Concerns about ecological integrity of nearshore marine ecosystems; • Concerns about decrease in demersal fish abundance and diversity; Neil McDaniel
• Concerns about decrease in average size of demersal fish;
WORLD’S
Underexploited 9%
MARINE
Biomass
Moderately exploited 23%
FISHERIES Fully to heavily exploited 44% Over-exploited 16% Depleted 6%
Recovering 3%
Fishing Mortality Botsford et. al. 1997
SOS
Georgia Strait Recreational Landings Rockfish Lingcod
100 80
500 450
250 200 150 100 50
1996
1994
1992
1990
1988
1986
0
1984
(Wallace 1999)
300
1982
1996
1994
1992
1990
1988
1986
1984
1982
1980
0
350
1980
20
400
1978
40
Landings (t)
60
1978
Landings (t)
120
(Wallace 1999)
DRIVERS • Need to address cumulative impacts; • Ecological integrity mandate; • Implementation of ecosystembased management approach by Parks Canada; • Need for an EI monitoring plan;
CUMULATIVE IMPACTS
ECOSYSTEM INTEGRITY "Unimpaired for Future Generations” • "An ecosystem has integrity when it is deemed characteristic for its natural region, including the composition and abundance of native species and biological communities, rates of change and supporting processes." Parks Canada 2001
STUDY LOCATION Broken Group Islands •H P B• • • • • J• •G • •T •
•
•O
E DS• • DW
• •
PROJECT OBJECTIVES OBTAIN:
Baseline data on the spatial distribution of nearshore demersal fish in BGI;
Baseline data on the abundance and diversity of nearshore demersal fish communities in BGI during summer and winter; Baseline data on fish communities associated with different habitats;
DEMERSAL FISH • • • • •
Commonly referred to as bottom fish; Living on or near the bottom; Resident, non-migratory species; Usually long lived; Examples include kelp greenling, rockfish, lingcod, perch, sculpins & gobies;
ROCKFISH ? • Order Scorpaeniformes Includes wide range of families (25) distributed from the Arctic to Antarctic;
• Family Scorpaenidae • Genus Sebastolobus 2 species in British Columbia
• Genus Sebastes There are 102 species worldwide and at least 35 species in British Columbia
ROCKFISH TRIVIA • Rockfish occupy a wide range of habitats and show high site fidelity; • Rockfish are long-lived species, some (e.g., rougheye rockfish) may live to at least 205 years; • Rockfish exhibit a wide range of maturation rates from 1-2 years (e.g., Puget Sound rockfish) to 22 years (e.g., yelloweye); • While most rockfish species are ovoviviparous (embryos develop within females but derive energy from egg yolks), some rockfish (e.g., copper, black) are viviparous (some energy is transferred from mother to the embryos);
SURVEY METHODS
Stratified random sampling; Sampling stratified into 4 habitat types (Macrocystis, Nereocystis, Eisenia and Rocky); Survey sites selected haphazardly; Number of survey sites in each habitat type; Replicates for each habitat;
VISUAL SURVEYS
Central transect
• Random 25 m x 2 m transects; • Paired observers; • Transects follow depth contour; • Identify species and record abundance, YOY; • Notations of visibility, temperature, habitat features, gravid females etc; 2m
2m
PACIFIC RIM NPR Common Fish Families
FAMILY
Common name
Cottidae Scorpaenidae Stichaeidae Pleuronectidae Embiotocidae Hexagrammidae Cyclopteridae Pholididae
Sculpins Rockfish Pricklebacks Righteye flounders Surfperches Greenlings Lumpfishes/Snailfishes Gunnels
• •
Species # 20 9 8 7 6 6 5 5
Fish families with 5 or more species found in the waters of Pacific Rim National Park Reserve Based on RBCM collections; 27 Families; 94 marine fish species represented in the collection.
COMMON SPECIES Species
Common name
Coryphopterus nicholsi Sebastes flavidus Brachyistius frenatus Sebastes caurinus Sebastes melanops Hexagrammos decagrammus Embiotoca lateralis Jordania zonope Rhacochilus vacca Cymatogaster aggregata Aulorhynchus flavidus Sebastes maliger Sebastes emphaeus Artedius spp. Artedius harringtoni
Blackeye Goby Yellowtail Rockfish Kelp Surfperch Copper Rockfish Black Rockfish Kelp Greenling Striped Surfperch Longfin Sculpin Pile Perch Shiner Perch Tubesnout Quillback Rockfish Puget Sound Rockfish Sculpin sp. Scalyhead Sculpin
Abundance / transect 28.36 10.54 5.61 5.57 5.18 4.18 3.08 2.66 2.36 1.26 0.90 0.78 0.77 0.48 0.38
RELATIVE OCCURANCE SPECIES % Occurance Copper Rockfish 100 Longfin Sculpin 100 Blackeye Goby 100 Striped Surfperch 100 Kelp Greenling 100 Yellowtail Rockfish 90 Pile Perch 90 Black Rockfish 80 Sculpin sp. 80 Quillback Rockfish 70 Kelp Surfperch 70 Painted Greenling 70 Lingcod 50
Species % Occurance Lingcod 50 Brown Rockfish 40 Puget Sound Rockfish 40 Scalyhead Sculpin 40 Shiner Perch 40 White-spotted Greenling 40 China Rockfish 30 Cabezon 30 Padded sculpin 30 Tubesnout 30 Vermillion Rockfish 20 Red Irish Lord 20 Saddleback gunnel 20
ROCKFISH SPECIES RICHNESS Species
Common name
Sebastes caurinus Sebastes flavidus Sebastes maliger
Copper rockfish Yellowtail rockfish Quillback rockfish Black rockfish China rockfish Canary rockfish Bocaccio Brown rockfish Puget Sound rockfish Vermilion rockfish Yelloweye rockfish Tiger rockfish Blue rockfish
Sebastes melanops Sebastes nebulosus Sebastes pinniger Sebastes paucispinis Sebastes auriculatus Sebastes emphaeus Sebastes miniatus Sebastes ruberrimus Sebastes nigrocinctus Sebastes mistinus
RBCM Study
+ + + + + + + -
+ + + + + + + + + + + +
ROCKFISH SPECIES RICHNESS Species richness
2.5
10
2.0 1.5
6
1.0
>
0.5
5
=
=
3
0.0 Prideaux
Turtle
Hand
Effingham
Location
Comparison of mean (± S.E.) rockfish species richness (S) per transect (25 x 2 m) among the 4 locations (winter & summer). Numbers above the error bars indicate the total number of rockfish (genus Sebastes) species recorded. One-way ANOVA: P < 0.000001.
ROCKFISH SPECIES RICHNESS Species richness
3.0
P > 0.15
2.5 2.0
P < 0.04
P < 0.01
1.5
P > 0.14
1.0 0.5 0.0 W
S
Prideaux
W
S
W
Turtle
S
Hand
W
S
Effingham
Location
Comparison of mean (± S.E.) rockfish species richness (S) per transect (25 x 2 m) among the 4 locations during winter (blue) and summer (red) months.
ROCKFISH ABUNDANCE Abundance (# / transect)
12 10
63
8 6 4
26
>
2
=
34
=
20
0 Prideaux
Turtle
Hand
Effingham
Location
Comparison of mean (± S.E.) rockfish abundance per transect (25 x 2 m) among the 4 locations (winter & summer). Numbers above bars indicate number of transects. One-way ANOVA: P < 0.000001.
ROCKFISH ABUNDANCE Abundance (# / transect)
12
P>0.256 10
P
48
0 Rocky
Eisenia
Macrocystis
Nereocystis
Habitats
Comparison of mean fish abundance (± STE) per transect among the 4 main habitat types. Numbers above STD error bars indicate sample size. One-way ANOVA (P < 0.00*) and results of the Tukey-Kramer multiple-comparison test.
d
/ transect
HABITAT COMPARISON 2.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00
= Rocky
> Eisenia
=
Macrocystis
Nereocystis
Habitats
Comparison of Margalef’s index of diversity (d) (± STD) per transect among the 4 main habitat types. Numbers above STD error bars indicate sample size. One-way ANOVA (P < 0.00*) and results of the Tukey-Kramer multiple-comparison test.
FISH / HABITAT ASSOCIATION (Summer + Winter)
Similarity
Average abundance
Canopy kelps
Understory kelps
Rock
FISH / HABITAT ASSOCIATION (SUMMER)
Similarity
Average abundance
Kelp
Rock
HABITAT SIMILARITY Relative abundance
E
R
Understory
Rocky
M
N
Canopy kelps
CHANGING VALUES • Aldo Leopold’s “Golden Rule of Ecology” asserts that:
“..a thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.” • In the decades that followed Leopold’s writings a number of scientists attempted to bring ecosystem concepts into natural resource management; • However, it was only relatively recently that these concepts began to take root in national policy;
TOWARDS ECOSYSTEM-BASED MANAGEMENT Sustainability: “… the maintenance of the potential of terrestrial and aquatic ecosystems to produce the same quantity and quality of goods and services in perpetuity.” (Franklin, 1993)
• “sustainability” - makes resource conditions the goal and precondition for meeting human needs over time; outputs are then “interest” on the capital;
• The use of the term “potential” makes implicit the option to return to alternative conditions, and makes it clear that ecosystem management does not necessarily require maintaining an existing condition.
ECOSYSTEM-BASED MANAGEMENT What is it? “….management driven by explicit goals, executed by policies, protocols, and practices, and made adaptable by monitoring and research based on our best understanding of the ecological interactions and processes necessary to sustain ecosystem composition, structure and function.” (Christensen et. al. 1996) (Parks Canada)
ECOSYSTEM-BASED MANAGEMENT Goals: • Maintain viable populations of all native species in situ; • Represent, within protected areas, all native ecosystems types across their natural range of variation; • Maintain evolutionary and ecological processes (e.g., nutrient cycles); • Manage over periods of time long enough to maintain the evolutionary potential of species and ecosystems; • Accommodate human use and occupancy within these constraints.
Special thanks to: Rick Holmes Pete Clarkson Bob Hansen Sebastian Marcoux Steve Lobay
Presented by Tomas Tomascik
[email protected]; Western Canada Service Centre
