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Reef Fishes in the Mariana Islands
Terry J. Donaldson
Reef Fishes in the Mariana Islands
University of Guam Marine LaboratoryUOG Station, Mangilao, Guam 96923 USAEmail: [email protected] JE Randall
Outline• Reef fish species diversity in the Mariana Islands: what weReef fish species diversity in the Mariana Islands: what we
know so far
H di i R f fi h i i G d th CNMI• Human dimensions: Reef fisheries in Guam and the CNMI‐following a global trend
• Human dimensions: Reef fish conservation and fisheries management strategies in Guam and the CNMI‐ following another global trendg
• Threats: To fish populations and assemblages, and to fisheries
• Research needs
• Mapping needs
Fish Diversity in the Mariana Islands
Over 1,048 species of inshore marine, estuarine and freshwater species
Other Surveys and Assessmentsy
• University of Guam Marine Laboratory collections y y(late 1960s to present)
• CNMI Division of Fish and Wildlife (Kate Moots and others)
• NOAA CRED research cruises
• NOAA/NMFS funded Bar Code of Fish Life sampling in Guam• NOAA/NMFS‐funded Bar Code of Fish Life sampling in Guam and the CNMI (University of Guam Marine Laboratory and collaborators)
Mariana Islands Fish Ecology: Habitat Association and Trophic Guilds
Donaldson (1995)
Human Dimensions and Reef Fisheries:The Usual Story‐y
Declines in Landings of Inshore Fishes
Richmond et al. (2008)
Russell et al. (2012)
Human Dimensions: Fish Conservation and Fisheries M t T l i G MPAManagement Tools in Guam‐MPAs
• Territorial Marine Protected Areas
Piti Bomb HolesSasa Bay Tumon BayTumon BayAchang BayPati Point
• Federal Marine Protected Areas
Northwest section of the Guam National Wildlife RefugeNorthwest section of the Guam National Wildlife Refuge,Ritidian
Marianas Trench Marine MonumentMarianas Trench Marine Monument
Fish Conservation and Fisheries Management Tools in th CNMI MPAthe CNMI: MPAs
• Commonwealth MPAsManagaha Marine Conservation Area, SaipanBird Island Marine Sanctuary, SaipanForbidden Island Marine Sactuary, SaipanSasanhaya Bay Fish Reserve, RotaNorthern Island protected areas
• FederalMarianas Trench Marine MonumentMarianas Trench Marine Monument
Effectiveness of MPAs as a Fish Conservation and Fisheries Management Tooland Fisheries Management Tool
Richmond et al. (2008)
Threats (Extrinsic Factors)• Over‐exploitationOver exploitation• Natural habitat destruction and loss
Volcanic eruptionsh kEarthquakes
TyphoonsCrown‐of‐thornsDisease
• Anthropogenic habitat destruction or lossOcean warming through anthropogenic climate changeOcean warming through anthropogenic climate changeOcean acidification through anthropogenic climate change
PollutionPollutionPoor land‐use practicesDestructive Fishing(The Usual Suspects)
Intrinsic Factors: Life History Traits and Distribution Patterns
Low actual or potential population growth rate indicated by any of theLow actual or potential population growth rate, indicated by any of the following:
• (i) Low fecundity • (ii) Late age at maturity (e.g. many groupers)( ) g y ( g y g p )• (iii) Large body size• (iv) Long generation time and/or longevity• (v) Low natural mortality (M)(v) Low natural mortality (M)• (vi) Depensatory dynamics at low numbers • (vii) Low intrinsic rate of population increase (r)
Ecological specialization, for example:• (i) Specialist feeding, breeding or nursery habitat (e.g. aggregations that
enhance catchability or close association with a susceptible habitat)y p )• (ii) Poor dispersal• (iii) Diadromy (where population is forced through a bottleneck)
Range size (i.e.. small or restricted range size)
Threats: Hyperstability and Hyperdepletion
Sadovy and Domeier (2005)
Extinction Susceptibility, Vulnerability and Risk in Coral Reef Fishes
Impacts of specialized habitats and specialized fish faunas
Population declines from over‐exploitation (intentional or masked)
Allee Effects retard resilience and recovery
Local extinctions
Loss of biodiversity
Coral reef system instability
Ecological shifts
Specialized Habitats: Reef Fish Spawning Aggregations, Their Utilization and Importance
Growth and sustainable use
Juvenile recruits(JE Randall)
Spawning aggregation speciesSuccessful spawning and dispersal of larvae
(JE Randall and DC Cook)
No spawning and ino recruitment
Fishing on spawning aggregations and no
spawningSpawning aggregation site Over‐exploitation
(TJ Donaldson; IMA) (TJ Donaldson)
Extinction Susceptibility and Vulnerability in Reef Fishes
Research Needs• Bar Code of Fish Life and cryptic speciesBar Code of Fish Life and cryptic species• Deep reef, shallow sea mount, and near‐shore pelagic fish
species diversityEl b h d t k l i f b h i• Elasmobranch survey and network analysis of behavior
• Fine scale diversity of offshore reefs• The geography of rarity versus commonality in relation to g g p y y y
biodiversity conservation• Habitat and microhabitat distribution, and utilization• Spawning aggregation identification distribution• Spawning aggregation identification, distribution,
characterization and function• Reproductive dynamics of spawning aggregation species• Connectivity at local and archipelago‐wide scales• Life history correlates of reef fishes• Predictions of extinction vulnerabilities in relation to threats• Predictions of extinction vulnerabilities in relation to threats
Mapping Needs
• Fish habitat and microhabitat in relation to the distribution of fish species
• Reef fish spawning aggregation sites (FSAS)
• Dispersal tracks of eggs and larvae from FSAS in relation to currents
• Characteristic fish assemblages
• Threats to fish assemblagesThreats to fish assemblages
• The geography of extinction