Cordell Bank National Marine Sanctuary
2009 Condition Report

Living Resources

The current state of living resources in the sanctuary is a snapshot in an evolving relationship between biological populations, physical processes and outside pressures. These pressures can be natural or human induced, and in many cases where populations fall to critically low levels, it is a combination of both. Many populations of fishes, marine mammals and seabirds are still recovering from historic declines caused by pollution, over-harvesting, destruction of habitat, and recruitment failure. Several species, like gray whales, brown pelicans and elephant seals, have experienced considerable population increases after exploitation or other human activities reduced their numbers dramatically. Other populations, like leatherback sea turtles, Chinook and coho salmon, and some species of rockfish, are at all time lows. In 2008, the commercial and recreational salmon season off the coast of California and Oregon was closed for the first time ever due to reduced population levels. And in recent years, jumbo squid populations have expanded to Cordell Bank from the south and have persisted in the area; this top-level predator has the potential to have significant impacts on the biodiversity and community composition within the sanctuary.

9. What is the status of biodiversity and how is it changing?

Species have probably not been lost from the marine ecosystem within the Cordell Bank sanctuary in recent history and it is likely that species richness has not declined. However, changes in the abundance of several key groups suggest that relative abundance of different species (species evenness) has changed and community composition has been altered. Changes in oceanic conditions in recent years (Peterson et al. 2006, Goericke et al. 2007) have likely altered productivity within the sanctuary, with consequent changes in abundance and distribution of many taxa, including krill, marine mammals, and seabirds. Further, depletion of rockfish stocks due to overharvesting, as well as poor recruitment, has likely affected both species composition and reduced rockfish biomass on Cordell Bank; however, recent stock assessments suggest that many populations of overfished species are increasing (Pacific Fishery Management Council 2006). In addition, the range expansion and recent addition of jumbo squid to the marine ecosystem in this area could have a large impact on community structure. In combination, these natural and human-induced alterations have diminished, to some extent, ecosystem integrity in both benthic and pelagic systems. For these reasons, the status of biodiversity in the sanctuary is rated as fair  and improving. 

The conditions of the following groups were used to assess the overall status of biodiversity:

• Benthic invertebrates: Overall biodiversity of benthic invertebrates on soft and hard substrates on the continental shelf appears healthy, based on limited observations (Cordell Bank sanctuary, unpubl. data). Photographs of the invertebrates of the reef top of Cordell Bank taken by Cordell Expeditions in the late 1970s (Schmieder 1991) reveal an assemblage very similar to that observed by sanctuary staff in 2005 (Cordell Bank sanctuary, unpubl. data), suggesting that current biodiversity of this group is stable. The condition of slope invertebrates is virtually unknown. 
  
  
• Pelagic invertebrates: Annual fluctuations in pelagic invertebrates are related to oceanic conditions; a warming trend in coastal oceans could affect population structure and species composition. The recent persistent residence of the jumbo squid within the region of the sanctuary (Zeidberg and Robison 2007) suggests the possibility that the marine ecosystem has been or will be altered by the addition of a top level predator, resulting in shifts in community composition.
  
  
• Fishes: Overharvest of some rockfish populations (i.e. yelloweye, canary, and cowcod), combined with poor recruitment, has severely impacted their populations along the west coast (Ralston 2002) and has resulted in the closure of some groundfish fisheries in an attempt to rebuild depleted populations (Figure 36). There is also some indication that the general removal of large predators (e.g., yelloweye rockfish) can alter species composition, allowing populations of smaller fishes (e.g., the pygmy rockfish (Sebastes wilsoni) and squarespot rockfish (S. hopkinsi)) to expand (Baskett et al. 2006). This process may help explain data from recent submersible observations on Cordell Bank, in which pygmy rockfish were the most abundant rockfish observed on Cordell Bank (Anderson et al. 2007, in review.).

  

  Closures associated with Rockfish Conservation Areas and Essential Fish Habitat Conservation Areas have been established; these protected areas will locally reduce fishing pressure and help rebuild depleted rockfish populations (see Figure 23, in pressures section). Population metrics from recent stock assessments indicate an increase in population abundance over the last five years for many overfished species, while populations of other species considered overfished appear to be stable (Pacific Fishery Management Council 2006). Lingcod are a top predator and their population has been declared rebuilt after consecutive years of good recruitment (Pacific Fishery Management Council 2006).

  

  Nevertheless, pelagic juvenile rockfish surveys in 2005 within the northern California region indicated an all time low in catch (for a 23 year data set) (Figure 37) and an apparent shift in distribution of fish to the north and the south of the central California region (Peterson et al. 2006; S. Ralston, NOAA's Southwest Fisheries Science Center, unpubl. data). A combination of instream pressures such as water diversion and degraded spawning habitat and poor ocean conditions have taken a toll on populations of Chinook and coho salmon. Poor spawning escapement and record low numbers in the ocean elicited an unprecedented closure of the commercial and recreational fall run Chinook salmon fishery in 2008.

• Seabirds: Locally breeding seabird populations within central and northern California have generally suffered long term declines (Ainley and Hyrenbach 2007). For example, the mean density of Ashy Storm-Petrels, Rhinoceros Auklets (Cerorhinca monocerata) and Western Gulls (Larus occidentalis) from at-sea surveys in northern California have declined significantly over the time period of 1985-1994 compared to 1997-2006 (Ainley and Hyrenbach 2007). Some locally breeding species (e.g., Cassin's Auklets) have experienced reduced reproductive success in recent years due to poor feeding conditions in the coastal ocean (Sydeman et al. 2006). Abundance of non-resident species, such as Sooty Shearwaters (Puffinus griseus) and Black-footed Albatrosses (Phoebastria nigripes), have also declined within the waters of northern California (Ainley and Hyrenbach 2007), potentially due to population declines resulting from human impacts in remote locations. 
  
  
• Marine mammals: Stock assessments suggest that many of the populations of marine mammals that use sanctuary habitats are stable or increasing. For example, there is evidence suggesting an increasing population for the eastern North Pacific humpback whale stock (Carretta et al. 2007). Nevertheless, the distribution and use of sanctuary habitats by some marine mammals (e.g., blue whale) in recent years (i.e., 2005-06) appears to have been altered (Peterson et al. 2006) due to a decrease in the overall abundance of krill in the area (Peterson et al. 2006, Sydeman et al. 2006, Jahncke et al. 2008).

10. What is the status of environmentally sustainable fishing and how is it changing?

The status and trend ratings for this question are based on the available scientific knowledge (e.g., published studies, unpublished data, and expert opinion) of targeted and non-targeted living resources that are directly and indirectly affected by fishing. The rating reflects a more historical view of the potential effects of fishing activity on biological community development, function, and ecosystem integrity, over the last two to three decades. The rating does not serve as an assessment of the status of current fisheries management practices in the region.  However, the determination of an increasing trend for this question does reflect recent changes in fisheries management practices and their positive effects on living resources in the sanctuary.

In the early 2000's, seven species of rockfish - widow (Sebastes entomelas), yelloweye (S. ruberrimus), canary (S. pinniger), darkblotched (S. crameri), bocaccio (S. paucispinis), cowcod (S. levis), and Pacific ocean perch (S. alutus) - were formally declared overfished throughout their range by the NOAA Fisheries (Figure 36); all but cowcod, Pacific ocean perch, and darkblotched rockfish are relatively common within the sanctuary (Anderson et al. in review). In addition, long lines, gillnets, and bottom trawls have negatively impacted seafloor habitats and benthic organisms in the sanctuary. For these reasons, this question is rated “fair.” However, the trend is considered to be “improving” because the management strategies used by NOAA Fisheries and the Pacific Fisheries Management Council (PFMC) have become much more restrictive since the Sustainable Fisheries Act was passed in 1998. Prohibitions associated with the Rockfish Conservation Area closures and regulations implemented in 2006 by Essential Fish Habitat (EFH) Conservation Areas are encouraging sustainable fishing practices by prohibiting the use of destructive gear types on selected benthic habitats (see Figure 23, in pressures section).

NOAA Fisheries conducts an annual survey to estimate the distribution and abundance of pelagic juvenile rockfish in the immediate region of the sanctuary (Figure 37). Results show that during the late 1980s, catches averaged 10-100 fish/trawl, but during the 1990s, there was a general decline in abundance, falling to 0.2 fish/trawl in 1998. Catches later increased to ~10 fish/trawl from 2001-04, but dropped abruptly to their lowest value in the time series in 2005 (0.1 fish/trawl). Since then, catches have increased slightly, but still remain low (0.4 fish/trawl in 2007). Trends in abundance of exploited and unexploited species are very similar, implying that variation in the environment is largely responsible for these trends (S. Ralston, NOAA's Southwest Fisheries Science Center, unpubl. data).

Management regimes for commercial fishing are currently more risk adverse than in prior decades, and some measures are proving successful in allowing over-fished stocks to recover. Many of the species are responding positively to management changes and are showing clear evidence of recovery based on stock assessments. For depleted rockfish species with stock assessment data, all are showing increasing trends in spawning biomass over the past 10 years. Contributing to these recoveries are gear changes to reduce by-catch, limits on the number of permitted vessels in the fishery, and several closures and restricted areas (e.g., Essential Fish Habitat bottom trawl closures and the Rockfish Conservation Area). Fishing for rockfish is prohibited within the Rockfish Conservation Areas but recovery of over fished species is expected to take some time due to slow maturity rates for these species. Lingcod was previously declared overfished but is now recovered; harvest restrictions proved successful, as the rapid growth and maturity of this species resulted in more rapid population increases than the over-fished rockfish species. The prohibition of both bottom trawling and use of bottom contact gear in Essential Fish Habitat (EFH) Conservation Areas, which were designated in 2006 in some offshore areas, is expected to increase habitat protection (Figure 23). In response to dwindling groundfish populations and in an effort to protect groundfish habitat, a series of prohibitions, quotas, and gear restrictions have made it less profitable to trawl and the number of active trawlers has declined.

11. What is the status of non-indigenous species and how is it changing?

A number of non-native species are present in the marine environment near Cordell Bank sanctuary, but none are known to currently exist in the sanctuary; however, there has not been a comprehensive inventory of species within the sanctuary. For this reason, this question is rated "undetermined" for both its status and trend. There is some concern regarding an invasive tunicate, Didemnum sp. that has been observed in nearby coastal areas and has covered large areas of Georges' Bank on the east coast (Bullard et al. 2007). The invasive tunicate is similar to a nativeDidemnum species and sampling will be necessary to determine which species is present on Cordell Bank.

12. What is the status of key species and how is it changing?

Key species were selected for several groups of animals inhabiting Cordell Bank National Marine Sanctuary. In some cases, local and migratory representatives were selected from one group to capture population changes that may be associated with pressures on different temporal and spatial scales. The following provides a summary for selected indicator species or groups:

• Reef-top Invertebrates: The upper reef areas of Cordell Bank shallower than 60 meters are covered with a rich and diverse assemblage of benthic invertebrates. Sponges, strawberry anemones, hydrocorals, and tunicates encrust rock surfaces, while more mobile sea stars, sea urchins and crabs move over the surface of this reef. Photographs taken by Cordell Expeditions in the late 1970s (Schmieder 1991) reveal a biological assemblage very similar to that observed by sanctuary staff in 2005 (Cordell Bank sanctuary, unpubl. data). 
  
  
• Krill: Krill are keystone species and large changes in population size are related to changing oceanic conditions. Reduced primary productivity in 2005 (Jahncke et al. 2008), which was associated with anomalous atmospheric conditions that delayed upwelling, limited krill population growth and impacted the condition of higher trophic levels dependent on krill (Sydeman et al. 2006, Jahncke et al. 2008).



• Rockfish: Rockfish are the dominant group of fishes on Cordell Bank, and status varies by species. In the early 2000's, seven species of rockfish - widow (Sebastes entomelas), yelloweye (S. ruberrimus), canary (S. pinniger), darkblotched (S. crameri), bocaccio (S. paucispinis), cowcod (S. levis), and Pacific ocean perch (S. alutus) - were formally declared overfished throughout their range by the NOAA Fisheries; all but cowcod, Pacific ocean perch, and darkblotched rockfish are relatively common within the sanctuary (Anderson et al. in review) (Figure 38).

  

  Population metrics from recent stock assessments indicate an increase in abundance over the last five years for many overfished species, while populations of other species considered overfished appear to be stable (Pacific Fishery Management Council 2006; Figure 36). Nevertheless, pelagic juvenile rockfish surveys in 2005 within the central and northern California region (Carmel to Bodega Bay) indicated an all time low in catch (for a 23 year data set) (Figure 37) and an apparent shift in distribution of fish both to the north and the south of the central California region (Peterson et al. 2006). There is also some indication that the general removal of large predators (e.g., yelloweye rockfish) can alter species composition, allowing populations of smaller fishes such as pygmy and squarespot rockfish to increase (Baskett et al. 2006). In recent submersible surveys of demersal fishes, pygmy rockfish were the most abundant rockfish observed (Anderson et al. 2007, in review).

• Sea Turtles: Between 1982 and 1996, the world population of leatherback sea turtles declined drastically, from 115,000 to 34,500 adult females (Spotila et al. 2000) and the population status is currently endangered. Much of the mortality occurs when eggs are harvested from beaches and adults are taken as bycatch in high seas fisheries. The northern California region, including the Cordell Bank sanctuary, is an important foraging area for adult leatherbacks in late summer and fall (Benson et al. 2007a). The occurrence of leatherbacks within the sanctuary is likely tied to changes in oceanic conditions and the availability of jellyfish (Benson et al. 2007a).
  
  
• Cassin's Auklet: Cassin's Auklets (Ptychoramphus aleuticus) nest on the Farallon Islands and use local sanctuary waters to feed (Jahncke et al. 2008, PRBO Conservation Science, unpubl. data, Cordell Bank sanctuary, unpubl. data), foraging primarily on krill. Abundance patterns of Cassin's Auklets from at-sea surveys in the central and northern California region (Monterey to Bodega Bay) indicate decreasing trends in abundance between the time periods of 1985-1994 and 1997-2006 (Ainley and Hyrenbach 2007). Further, complete reproductive failure of Cassin's Auklets on the Farallon Islands in 2005 and 2006 related to anomalous oceanic conditions and poor early season productivity (Figure 39, Sydeman et al. 2006, Peterson et al. 2006, Goericke et al. 2007, PRBO Conservation Science, unpubl. data) may have long term impacts; however, recent data suggest the population is rebounding (Figure 39; PRBO unpubl. data).






• Black-footed Albatross: Black-footed Albatrosses (Diomedea nigripes) nest on the northwestern Hawaiian Islands and are seasonally common and can be locally abundant within the sanctuary in the summer (NCCOS 2007, Cordell Bank sanctuary, unpubl. data, PRBO Conservation Science, unpubl. data). Analysis of nest count data of Black-footed Albatrosses from Midway, Laysan, and the French Frigate shoals indicated an increasing trend in breeding birds over the long time period (1922-2005), but a declining trend in the breeding population over the past 15 years (Naughton et al. 2007). Similarly, local patterns of Black-footed Albatross abundance in the central and northern California region (Monterey to Bodega Bay) from at-sea surveys indicate an average decrease in density of 18% between the time periods of 1985-1994 and 1997-2006, and overall cyclical trends in abundance (Ainley and Hyrenbach 2007). Populations are impacted by long-line mortality in areas outside of the sanctuary (Lewison and Crowder 2003), these impacts could eventually be observed at the Cordell Bank sanctuary. These albatrosses are also known to ingest and feed plastic to chicks, which can as a result die of starvation (Sievert and Sileo 1993, Gould et al. 1997). However, because albatrosses live up to 50 years, the influence of these impacts on population trends and the abundance of birds in the sanctuary are slow to emerge.
  
  
• Sooty Shearwater: Sooty Shearwaters (Puffinus griseus) are one of the most abundant seabirds in the sanctuary (Cordell Bank sanctuary, unpubl. data) as well as in the California Current System during summer (Figure 40). 

  

  Flocks with thousands of individuals pass through the sanctuary in summer and fall (NCCOS 2007, PRBO Conservation Science, unpubl. data, Cordell Bank sanctuary unpubl. data), feeding in the productive waters of the northeast Pacific while away from their nesting islands in Chile and New Zealand. Worldwide populations are currently in decline, with high mortality due to bycatch in various fisheries (U.S. Fish and Wildlife Service 2006). Local patterns of Sooty Shearwaters from at-surveys in the central and northern California region (Monterey to Bodega Bay) also indicate decreasing trends in abundance between the time periods of 1985-1994 and 1997-2006 (Ainley and Hyrenbach 2007).
  
  
• California sea lion: California sea lions (Zalophus californianus) are one of the most abundant pinnipeds found in the sanctuary, with highest abundance from summer through early spring (Cordell Bank sanctuary, unpubl. data) when animals are not on the breeding grounds on the Channel Islands and Ano Nuevo. Data suggest that El Nino events (depending on severity, timing, length, and frequency) decrease the population growth rate (Caretta et al. 2007) as well as their distribution and abundance within the area (Lowry and Forney 2005). In recent years, the population has been growing at 5.4% to 6.1% per year (Carretta et al. 2007).
  
  
• Humpback whale: Cordell Bank and the other West Coast sanctuaries provide important foraging grounds for humpback whales (Megaptera novaeangliae), which are seasonally abundant, migrating into the sanctuary during late spring, summer and fall to feed in its productive waters (NCCOS 2007, PRBO Conservation Science, unpubl. data, Cordell Bank sanctuary, unpubl. data). They are generalist feeders, but prey heavily on small schooling fish and krill. The eastern north Pacific stock is listed as federally endangered, and there is evidence to suggest a positive population trend (Carretta et al. 2007).
  
  
• Blue whale: Cordell Bank and the other west coast sanctuaries provide important foraging grounds for migrating blue whales (Balaenoptera musculus) in summer and fall (NCCOS 2007). These whales feed primarily on krill; thus, their use of sanctuary habitats is expected to vary with krill abundance. A change in the distribution of blue whales in 2005 and 2006 (PRBO Conservation Science, unpubl. data, Cordell Bank sanctuary, unpubl. data) is probably a response to changing oceanic conditions and reduced krill abundance in the region during these years (Peterson et al. 2006). The population of the eastern north Pacific stock of blue whales appears to be growing (Carretta et al. 2007).

13. What is the condition or health of key species and how is it changing?

The condition or health of key species in the sanctuary is rated as good  and not changing.  Research conducted at Cordell Bank in the 1980s (Okihiro et al. 1992) documented the occurrence and frequency of lesions on several species of rockfish, but the cause was not determined. Mortality events for some marine mammals and seabirds are related to domoic acid poisoning associated with red tides  or phytoplankton blooms (Scholin et al. 2000, Work et al. 1993). These events are often discovered when organisms wash up on beaches and have not been linked to the Cordell Bank sanctuary. The occurrence of domoic acid poisoning appears to be more prevalent in southern California, but events have occurred as close as Monterey Bay (Work et al. 1993).

Natural fluctuations in body condition and health of key species are caused by changing oceanic conditions that affect food supplies. Reduced ocean productivity resulting from anomalous conditions has been related to poor condition of seabirds (Sydeman et al. 2006), marine mammals and fishes. While these biological conditions are thought to be primarily a result of natural variations, the sanctuary is concerned that continued ocean warming, changes in upwelling timing and intensity, and reduced productivity associated with long term climate change could impact the condition and health of key species.

14. What are the levels of human activities that may influence living resource quality and how are they changing?

The levels of human activities that may influence living resource quality in the offshore environment are rated "fair" and "improving." Specific activities that have the potential to influence living resource quality include fishing and associated habitat disturbance, vessel traffic (discharge, oil spills, noise, collision), and marine debris (derelict gear and plastics), all of which may influence living resource quality in the sanctuary. Fishing activity has been severely restricted to protect habitat and overfished rockfish populations (see Figure 23, in pressures section) and overall landings of various fisheries have declined in recent decades (Figure 21). Shipping activity remains constant, averaging about 2000 commercial vessels a year passing through the sanctuary (U.S. Coast Guard, unpubl. data). The amount of derelict fishing gear should not be increasing within the sanctuary, due to the current restrictions on bottom tending fishing activities. It is unknown how growth in the human population, especially in coastal areas, is impacting the levels of other marine debris types.

Living Resources and Trends

Status:   Good     Good/Fair      Fair      Fair/Poor      Poor       Undet.  

Trends:

▲ Conditions appear to be improving.
▬ Conditions do not appear to be changing.
▼ Conditions appear to be declining.
? Undeterminted trend.
N/A Question not applicable.