ABOUT THE PROJECT

The Gulf of California has been historically characterized by high levels of marine biodiversity and productive small-scale fisheries. These characteristics are threatened by overfishing. Enhanced marine management is needed to reverse ecological degradation and sustain the ecosystem’s capacity to provide goods and services, including vital fisheries. Marine reserves are a management tool that close off areas of the ocean to fishing, allowing fish inside the reserves to increase in size and number. Theoretically, spillover occurs when fish move across the boundary of a reserve where fishers can benefit. Comunidad y Biodiversidad (COBI) presented a marine reserve network design to the Mexican government in 2015 that would protect 5% of the Midriff Islands. To date, the marine reserve network has not been implemented.

Midriff Island Region outlined in blue

Proposed marine reserve network shown in brown

Our Research Question

Trade-offs associated with marine reserves are believed to have played a key role in the network’s delayed implementation; potential long-term gains in sustainable fishing and the conservation of biodiversity likely generate short-term losses in fishery revenue due to fishery closures. The trade-offs between conservation and livelihood led our team to ask:

What are the consequences of delaying the implementation of a reserve network, and how much area should be protected to enhance both fish biomass and catch?

Scenarios Analyzed

COBI's Design

Conservation

Livelihoods

Food Security

Quantified changes in biomass and catch of fisheries in the region over the projected time frame if COBI's design had been implemented when proposed in 2015.

Quantified which marine reserve scenario resulted in the largest amount of biomass during the projected time frame.

Quantified which marine reserve scenario resulted in the earliest pay off year during the projected time frame.

Quantified which marine reserve scenario resulted in the largest amount of catch during the projected time frame.

Results from Scenarios

COBI's Design

The proposed design is a 5% marine reserve network that is implemented in 2015, where illegal fishing is neither accounted for nor addressed. Implementation of the reserve never pays off, and changes in biomass and catch are not substantial.

Conservation

If the proposed design is increased to protect 50% of the region, implemented in 2015, and illegal fishing is accounted for and addressed, the transition period ends in 2025, and the lost catch due to the closure of fishing grounds will be recovered by 2037.

Livelihoods &
Food Security

If the proposed design is increased to protect 30% of the region, implemented in 2015, and illegal fishing is accounted for but not addressed, the transition period ends in 2019, and the lost catch due to the closure of fishing grounds will be recovered by 2022.

Headline photo: Octavio Aburto
Inside photos: COBI
Icons:  COBI