Do Marine Protected Areas Protect Fish?

Do Marine Protected Areas Protect Fish?

Why do we set up MPAs? To protect Areas Managaha Island Invertebrates Octopus, etc Corals All Fish All well that s the idea Historical sites Managaha Island (WWII and Carolinian sites) Cultural sites Managaha Island (Carolinian sites)

Do they protect these things? Depends on a lot of factors First we have to look at boundaries Are the things we are trying to protect found within the MPA?

How do we set boundaries? To include certain areas Managaha Island Natural features Lagoon and outer reef Politics Law was made by Legislature Ease box around Managaha What to exclude shipping channel

Are they set with our conservation goals in mind? Sometimes Certain areas Natural features Sometimes Not Politics Ease Natural features

Boundaries encompass stationary goals easily Everything except fish and invertebrates stationary How often are they there? How important is the area to them?

How do we assess our boundaries and goals Stationary goals (corals, etc) visual monitoring Fish and inverts visual monitoring is possible but does it address what you want to know? Fish and inverts don t know about the boundaries and can traverse them at any point A fish seen inside the MPA may live 95% of its life outside and vice versa.

How to monitor fish movements Physically follow individual fish Difficult, large degree of survey impact on the fish, time consuming, small sample size Constant record of where the fish is, Minimal training needed Mark, recapture (possible future project) Requires large amounts of tagged fish, large sampling regime to recapture, large effort for recaptures, only get 2 points of data for each fish Large sample size, Minimal training needed, relatively cheap

How to monitor fish movements Tagging fish with ultrasonic transmitters and monitoring with a passive array Expensive, requires specialized skills (surgical implantation), Initially high time requirement Record multiple locations for fish with minimal influence from recording process, Long term low time requirement, requires only periodic downloading of data

Looking at fisheries in the Lagoon Managaha likely provides direct spillover into lagoon fisheries Rod and reel shore fishery is important in the lagoon Thumbprint emperor Lethrinus harak is one of the most common catches.

Questions about the relationship between MMCA and L. harak What habitats do L. harak use? Do Lethrinus harak use MMCA? How much? Which parts? Does MMCA protect L. harak? Do all the habitats it uses occur within MMCA? Do enough of the habitats it uses occur in MMCA? Do some/all/no L. harak stay completely within MMCA? Do some/all/no L. harak leave MMCA?

What habitats do they use?

Do fish use MMCA? How much? Which parts?

Which parts?

Does MMCA protect L. harak? Habitat Home range

How does this affect management? Over time look at other species Learn how different species use the area How effective the MPA is for various fishes Some maybe not as effective as others Gives us information that we can use when adjusting MPAs and making management decisions Important to gain local movement data

Scale of Movement for Various Fishes Maypa et al 2012

Moral of the story MPAs are thought to protect fisheries, but often fisheries aren t really considered when making boundaries. Studying fish use within and around MPAs allows us to make better decisions in the future and see which fish our MPAs really protect.

Take Away Message If you see any of these tagged fish, DFW would appreciate you not taking them so we can get more movement data from the fish. If you do take them DFW would like to examine the fish to measure it and remove the tags. It is LEGAL to take tagged fish outside of MPAs through legal methods but please inform DFW if you do.

Questions