Review of California halibut trawl fishery in the California halibut trawl grounds

(Document pdf contains 44 pages

Review of the California Trawl Fishery for Pacific Ocean Shrimp, Pandalus jordani, from 1992 to 2007

The commercial bottom trawl fishery for Pacific ocean shrimp, Pandalus jordani, or pink shrimp, operates mostly off the west coast of the contiguous United States. The California portion of the fishery has not been thoroughly documented or reviewed since the 1991 fishing season, despite its fluctuating more during the last 16 years (1992–2007) than at any other period in its 56-year history. We used fishery-dependent data, California Department of Fish and Game commercial landing receipts and logbook data, to analyze trends and review the California pink shrimp trawl fishery from 1992 to 2007. In particular, we focus on the most recent years of the fishery (2001–07) to highlight the gear developments and key management measures implemented in the fishery. The fishery is primarily driven by market conditions and is highly regulated by both state and Federal management agencies. Several key regulatory measures implemented during this decade have had significant effects on the fishery. For example, the requirement of a Bycatch Reduction Device on trawl nets targeting pink shrimp was approved in 2001 and has greatly reduced levels of finfish bycatch. Fishery production has declined, particularly in recent years, and may be attributed to decreased market prices, followed by reduced fishermen participation; both of which are related to changes in the processing sector and demand for the product

Experimental effects of black brant herbivory and fecal addition on the eelgrass animal community in Humboldt Bay, California, USA

Seagrass beds are productive, structurally complex ecosystems that support an abundant and diverse assemblage of animals. Although light is clearly important to seagrass productivity, grazers also alter this aspect of plant communities. Grazers may indirectly affect the associated animal community but this perspective has not been rigorously examined in temperate western North American seagrass beds. My thesis objective was to experimentally examine the effects of Pacific black brant geese (Branta bernicla nigricans) grazing and fecal addition on the abundances and sizes of the animals within an eelgrass (Zostera marina) bed of Humboldt Bay, CA (40º 43.1’ N, 124º 13.3’ W). In situ brant simulations were used to investigate the effects of different treatments (clipping, fecal addition, the combination of both at “intermediate” and “intense” levels, and brant exclusion) on the abundances and sizes of the animals within the Z. marina community. Animal treatment responses were only compared when Z. marina vegetation structure (shoot density, shoot length) significantly differed among treatments. By including covariates like climate and water quality variables, as well as distance of a treatment from channels, this study also identified the recruitment and environmental conditions that favor the development of a positive or negative relationship between animal abundance and size versus Z. marina complexity. For example, large interannual variation in juvenile Dungeness crab (Cancer magister) abundance was attributed to warmer water current structure changes during 2005, and may have therefore delivered fewer megalopae to Humboldt Bay. Similarly, the effects of fish predation may have equalized the abundance and distribution of small Z. marina invertebrates, such as caprellid and gammarid amphipods and bay isopod (Idotea resecata), and thus prevented a relationship with vegetation structure from developing. Following the effects of climate on recruitment and fish predation, brant induced changes to the vegetation structure did affect animal abundances and sizes, but responses were species-specific. The abundance of Taylor’s sea hare (Phyllaplysia taylori) increased when a maximum number of shoots were created by intermediate levels of brant grazing, and both the abundance and size of P. taylori decreased in response to shorter shoots created by intense levels of brant grazing. Other animal responses responded negatively to brant induced changes to the vegetation structure. For example, I. resecata were smaller when shoots were more dense and longer, and they were larger when shoots were less dense and shorter. Lastly, the abundances and sizes of some animals were significantly different among brant simulation treatments, but animal differences did not parallel the brant induced changes to the vegetation. Therefore, brant induced changes to the structural complexity of Z. marina affect both the abundance and size of the associated animal community under a limited set of circumstances

Designing a network of marine protected areas in California: Achievements, costs, lessons learned, and challenges ahead

The State of California recently planned and is implementing a network of marine protected areas (MPAs) in state waters as mandated by the Marine Life Protection Act (MLPA). A public-private partnership (the MLPA Initiative) completed four regional public MPA planning processes characterized by robust stakeholder contributions and the incorporation of best readily available science. Prior to enactment of the MLPA in 1999, less than 3% of California state waters were in MPAs, and most of those MPAs were small and lacked clear objectives. By 2013, approximately 16% of state waters will be in 124 MPAs that represent and replicate most marine and estuarine habitats and are designed to be ecologically-connected. The redesigned statewide network of MPAs improves marine ecosystem protection in California, advanced the science and practice of designing MPA networks, and increased the awareness and capacity of stakeholders, scientists and decision-makers for marine spatial planning. The public planning effort took almost seven years and significant financial investment (approximately $19.5 million in private charitable foundation funds and$18.5 million in public funds). Not all stakeholders were pleased with the outcomes and the planning processes faced many challenges. While the design of the MPA network aimed to meet science and feasibility guidelines, final decisions on MPAs in each region reflected tradeoffs needed to garner public acceptance and support for implementation. The MLPA Initiative offers some key lessons about implementing policy through a public planning process. While California is developing mechanisms for assessing effectiveness of the MPA network in coming years, including establishing a MPA Monitoring Enterprise and a process for periodic review and adaptive management of MPAs, significant challenges remain for effective implementation. © 2012 Elsevier Ltd

Designing a network of marine protected areas in California: Achievements, costs, lessons learned, and challenges ahead

The State of California recently planned and is implementing a network of marine protected areas (MPAs) in state waters as mandated by the Marine Life Protection Act (MLPA). A public-private partnership (the MLPA Initiative) completed four regional public MPA planning processes characterized by robust stakeholder contributions and the incorporation of best readily available science. Prior to enactment of the MLPA in 1999, less than 3% of California state waters were in MPAs, and most of those MPAs were small and lacked clear objectives. By 2013, approximately 16% of state waters will be in 124 MPAs that represent and replicate most marine and estuarine habitats and are designed to be ecologically-connected. The redesigned statewide network of MPAs improves marine ecosystem protection in California, advanced the science and practice of designing MPA networks, and increased the awareness and capacity of stakeholders, scientists and decision-makers for marine spatial planning. The public planning effort took almost seven years and significant financial investment (approximately $19.5 million in private charitable foundation funds and$18.5 million in public funds). Not all stakeholders were pleased with the outcomes and the planning processes faced many challenges. While the design of the MPA network aimed to meet science and feasibility guidelines, final decisions on MPAs in each region reflected tradeoffs needed to garner public acceptance and support for implementation. The MLPA Initiative offers some key lessons about implementing policy through a public planning process. While California is developing mechanisms for assessing effectiveness of the MPA network in coming years, including establishing a MPA Monitoring Enterprise and a process for periodic review and adaptive management of MPAs, significant challenges remain for effective implementation. © 2012 Elsevier Ltd