A New Type of Conservation

Protecting Seabirds and Marine Mammals with the MLPA

Brandt's Cormorant. Credit MojosCoast

By Irina Kogan

The Marine Life Protection Act (MLPA) aims to protect and restore ecosystems by conserving habitats and the species dependent on those habitats by creating zones in the ocean.  Although these zones, called Marine Protected Areas (MPAs), generally restrict extraction, it was clear early on in the stakeholder-driven process that North-central California, specifically the Gulf of the Farallones and northern Monterey Bay Sanctuaries, is a marine wildlife hotspot needing additional protection.  The area is home to the largest concentration of breeding seabirds in the contiguous US and a richly-diverse population of marine mammals.

The uniqueness of the region and the threats to its resources prompted the Gulf of the Farallones National Marine Sanctuary in partnership with other agencies and stakeholders to recommend special protection, called Special Closures, for the most at risk seabird and marine mammal species by minimizing human-based disturbance at the most critical breeding and resting areas.

On April 23, 2008, for the first time in the implementation of the MLPA, the Blue Ribbon Task Force, an advisory group to the California Department of Fish and Game Commission, made a decision to forward four MPA network proposals that contained Special Closures.

Seabirds and marine mammals such as seals and sea lions are highly sensitive to human disturbance. These animals depend heavily on the ocean for food but come on shore to breed and rest. Seabird colonies are typically located on offshore rocks, isolated sea stacks, islands and steep mainland cliffs –areas that can usually only be accessed by boats. Seals and sea lions also tend to use remote areas.

Single disturbance events or chronic disturbance can result in the loss of an entire generation of seabirds at a colony and mortality of seal or sea lion pups. Special Closures at key sites are anticipated to aid breeding success of at-risk species, increase their populations, and help them recover from oil spills. More information on how human-based disturbance affects seabirds can be found on the Sanctuary’s Seabird Colony Protection Program website.

Special Closures are relatively small (300 to 1000 ft diameter) vessel no-go zones designed to protect key marine wildlife hotspots from boat-based human disturbance. Boats, including kayaks, wildlife viewing boats, commercial and recreational fishing vessels, private motorized vessels and jet skis have been documented sources of human disturbance in this region.

Although low flying airplanes and humans on foot also cause disturbance, seabird monitoring indicates that boats have caused the most severe observed impacts at the monitored sites. Impacts are mostly from vessels approaching, anchoring, drifting, or lingering in close proximity to a colony.

Monitoring data indicates that a 1000 ft Special Closure would eliminate 92% of seabird disturbance events while a 300 ft Special Closure is likely to eliminate 68% of seabird disturbance events (G. McChesney, personal communication). 300 ft is the recommended distance associated with the Marine Mammal Protection Act to avoid seal and sea lion disturbance. Although Steller sea lions, a listed species under the Endangered Species Act, require 3000 ft of Critical Habitat around designated rookeries.

Special Closure sites were chosen sparingly and were placed in areas with the highest species diversity, abundance, presence of recovering species and/or species in decline: (They include) the Farallon Islands, Drakes Bay, Point Reyes, and Devil’s Slide Rock. Particular species of concern are local populations of Common Murres, Pelagic Cormorants, Pigeon Guillemots, and Steller sea lions that remain below historic levels. Click for more information on the Common Murre Restoration Project.

The Sanctuary worked with a diverse community of stakeholders to develop Special Closures while accommodating user interests. Staff worked with over 60 individual stakeholders who represented commercial fishing, recreational fishing, seabird/marine mammal viewing ecotourism, shark ecotourism, diving, small boating, and surfing interests. Compromises were forged that accommodated existing uses and navigational safety while providing critical protection for key species and areas.

Click here for Summary of Special Closures in the North-Central Coast MLPA Integrated Preferred Proposal.

The next step in MLPA implementation for the North-Central coast is a meeting where all recommendations are forwarded to the California Department of Fish and Game Commission (Commission). The Commission is anticipated to hold public hearings during summer and fall of 2008 and make a decision on its preferred option in winter 2008-2009. A California Environmental Quality Act (CEQA) analysis of all potential options and a final decision will follow.