Science-based “rules of thumb” for the design of marine protected area networks Mark H. Carr Dept. of Ecology and Evolutionary Biology, University of California, Santa Cruz Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO)

Design Principles reflect MPA conservation goals reflect fundamental ecological processes reflect human dimensions planning process that engages stakeholders science guidance that is transparent, credible, responsive, understandable – “rules of thumb” Science guidance needs to explain and becommunicated in ways that are understandable make sense

California MLPA: Conservation Goals Protect natural diversity and ecosystem functions Protect representative and unique habitats Sustain and restore marine life populations Ensure that MPAs are designed and managed as a network NOTE: the lack of any reference to fisheries management or impacts!!

Design Criteria – MPA Network Habitat (ecosystem) representation Habitat (ecosystem) and MPA replication MPA size MPA spacing Conservation level What level of conservation or protection is afforded species and ecosystems based on the activities that might be allowed in an MPA?

Habitat and Ecosystem Representation Identify ecosystems based on: Bottom type and depth Biogenic habitat (kelps, corals, sponges) Oceanographic features To identify those ecosystems, we use… and consider… Estimate habitat distribution and abundance using GIS 5

Ecosystems vary by bottom type and depth

Ecosystems vary geographically West Islands North Mainland Mid Islands East Islands South Mainland Between and within biogeographic regions

Ecosystem Representation “rules of thumb” represent each ecosystem in MPAs across the network include habitats across a range of depths represent each ecosystem within and across biogeographic regions In contrast to Jon’s terminology, habitats here are substrates (rock vs. sand) X key habitats 16 habitat types

Design Criteria – MPA Network Habitat (ecosystem) representation Habitat (ecosystem) and MPA replication MPA size MPA spacing Conservation level

Ecosystem and MPA Replication Why replicate ecosystems and MPAs in a network? spread the risk of losing entire conservation tool to a local disturbance enhances representation replicate both the ecosystem and the type of MPA critical to evaluation and adaptive management

Ecosystem and MPA Replication What counts as an ecosystem replicate? 10 20 30 40 50 60 70 80 Square KM (or linear distance along coastline) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Estimated proportion of species should be sufficient to encompass most of the species that live in the habitat more area captures more species should be sufficient to capture 90% of biodiversity

Ecosystem and MPA Replication “rules of thumb” replicate ecosystems and MPA types across the network replicate within and across biogeographic regions sufficient area of ecosystem to contribute to network replicate each ecosystem in at least 3-5 MPAs within a region In contrast to Jon’s terminology, habitats here are substrates (rock vs. sand) X key habitats 16 habitat types

Design Criteria – MPA Network Habitat (ecosystem) representation Habitat (ecosystem) and MPA replication MPA size MPA spacing Conservation level

MPA Size MPAs must be large enough so that adults remain within them throughout their lifetime MPAs must be large enough to include multiple ecosystems to protect ecosystem connectivity Achieving these goals are all about proper size and spacing among reserves. The two fundamental criteria are that… This is not to imply that they need to be big and next to one another, rather as I’ll show you, there is a tradeoff between size and spacing.

Larger MPAs Protect More Species More flatfish Salmon Some schooling fish Few reef fish 100 – 1000 km > 1000 km Some schooling fish Tunas Many sharks 10 – 100 km Some reef fish Some flatfish 1 – 10 km More reef fish 0 – 1 km Many reef fish

MPA Size Guidelines “rules of thumb” Minimum area of 25 – 50 km2 Preferably 50 – 100 km2 Extend from the intertidal zone to deep waters, encompassing multiple ecosystems 25km2 = 9nm2 50km2= 16nm2

Design Criteria – MPA Network Habitat (ecosystem) representation Habitat (ecosystem) and MPA replication MPA size MPA spacing Conservation level

MPA Spacing MPAs must be close enough together that young (larvae) can move from one protected ecosystem to another MPAs contribute to replenishing one another and the fished populations in between them Achieving these goals are all about proper size and spacing among reserves. The two fundamental criteria are that… This is not to imply that they need to be big and next to one another, rather as I’ll show you, there is a tradeoff between size and spacing.

Populations Are Connected by Dispersal of Young Populations contribute to replenishment of one another Increase overall area replenished outside reserves per unit area within reserves Although adults of many species have very limited home ranges, their young can move great distances. Most marine species produce young (called larvae) that are carried off by ocean currents, to end up replenishing populations somewhere else along the coast. Therefore, to assure that the young produced in a reserve replenish other reserves and the populations in between, reserves need to be spaced from one another in relations to how far these larvae travel.

Size and Spacing Guidelines rules of thumb Size Spacing Size: 25-100 km2 Spacing: 50 – 100 km apart Tradeoffs in size and spacing Number of Species Here’s a graph that shows the number of algae, invertebrate and fish species whose young disperse the distance indicated along the bottom axis. Note that these distances are logarithmic scales increasing by an order of 10. Most of the seaweeds produce young that travel no more than a few kilometers. Invertebrates vary across the board, from meters to 100’s of kilometers, and larval fishes move the greatest distances from 10’s to 100’s of kilometers. Algae and many species of invertebrates will replenish their populations within reserves on the order of 10 km. (SPACE) But the young of many species travel far beyond the size of a single reserve, suggesting that reserves should be spaced no more than 50 to 100 km apart from one another. (SPACE) (SPACE) Note that size and spacing are inter-related. The smaller the reserve, the more and closer together they need to be. The larger the reserve, the farther apart they can be. Data from Kinlan and Gaines 2003, Shanks et al 2003

MPA Spacing Guidelines “rules of thumb” maximum distance between protected ecosystems of 50 – 100 km assessed separately for each ecosystem can be constrained by distribution and availability of ecosystems achieved most easily with multiple ecosystems in each MPA

Design Criteria – MPA Network Habitat (ecosystem) representation Habitat (ecosystem) and MPA replication MPA size MPA spacing Conservation level

MPA Conservation Levels if MPAs allow human activities, their conservation level may be diminished predict ecosystem conservation level by comparing to no-take marine reserve consider potential impacts to habitat, abundance of any species, community structure

MPA Conservation Levels “rules of thumb” only MPAs with high ecosystem conservation levels should count toward achievement of design guidelines

Conclusions - “rules of thumb” based on MPA conservation goals and ecological processes critical to transparent, credible, responsive, understandable science -based design of MPAs facilitates engagement of stakeholders in planning processes

Thank You Science Advisory Team Stakeholder Groups Design and application of support tools are a direct reflection of the planning process they were designed to facilitate, so it is necessary to quickly describe the MLPA planning process… using the MLPA goals, the science team was tasked with… Create and present guidelines Evaluate design proposals Design and propose MPAs and networks

The Product: MPAs established between 2007 and 2012 in four coastal regions 63 no-take reserves; 1291 km2, 9.4% of state waters 124 MPAs total covering 2197 km2, 16% of state waters The central coast effort created a regional network of reserves and conservation areas (these CA’s allow some forms of fishing). 10 fully protected no-take marine reserves covering roughly 8% of the region for a total of 29 marine protected areas were created. And as I mentioned, the network in the section of coast is in its final stages of design as well. 27