|Human Impacts on Marine Mammal Health |
Marine mammals along the California coastline and within our marine sanctuaries are vulnerable to the effects of human activities. The impact on marine mammal health may be direct and obvious, such as mortality due to gunshot wounds and entanglements, or indirect and harder to detect. These influences have been seen in marine mammals within the marine sanctuaries off the California coast through thorough examination of stranded animals as well
as monitoring the health of animals handled during management activities.
Stranded animals are more likely to be the sickest animals of a wild population and thus are useful to sample in order to identify and detect diseases. Surveys of stranded California sea lions' genetics have revealed that those dying with infectious diseases are more likely to be inbred than sea lions dying from trauma. Mortality is easy to detect, but subtle effects on the immune system and reproduction require specialized diagnostic tests adapted for use in marine mammals.
|Marine mammals are susceptible to infection by agents in terrestrial runoff or sewage. (Photo by Robert Schwemmer/NOAA)
Direct disturbances include wounds and mortality due to gunshot (8 percent of stranded California sea lions examined by The Marine Mammal Center are shot); entanglements in marine debris such as packing straps and fishing gear; vessel strikes; contamination from oil spills; and ingestion of fish hooks and sinkers. The latter may cause perforation of the esophagus or stomach that can result in infection and death: unusually, this year a harbor seal from San Francisco Bay died due to lead poisoning after ingesting a lead sinker. This animal had previously been observed rearing a pup
on rocks under the Richmond Bridge in San Francisco Bay, and
it stranded with neurological signs weeks later. A large salmon
flasher and lead sinker were found in its stomach, and lead levels in the seal's blood were extremely high.
Vessel interactions vary from propeller cuts that seriously injure or kill smaller marine mammals such as otters, seals and sea lions to blunt trauma from ship hulls that fracture the skulls of large humpback whales. The largest victim of a ship strike in recent years was an 80-foot-long female blue whale found floating off
the Golden Gate with four large gashes along its back and flank due to propeller cuts. The most obscure entanglement in recent years was the strangulation of an elephant seal by a toilet seat around its neck: this animal was saved by University of California researchers who managed to remove the seat.
People's acts affect marine mammal health indirectly, also. This can occur in a number of ways, such as through infection by agents in terrestrial runoff or sewage including bacteria and protozoa;
persistent organochlorines and heavy metals accumulating in the marine ecosystem due to industrialization; and disturbance due to increased noise generated by maritime shipping, offshore drilling, seismic surveys and military activities.
Recently identified parasites in marine mammals include Giardia lamblia, Sarcocystis neurona and Toxoplasma gondii, which are all capable of infecting humans and are likely of terrestrial origin. Toxoplasma gondii relies upon a cat (wild or domestic felid) to maintain its life cycle, so its presence in sea otters, dolphins, seals and sea lions is unusual and raises questions about how it has reached these marine mammal hosts, which have no direct contact with cats. Bacteria such as Salmonella and Campylobacter, known causes of diarrhea in humans and terrestrial livestock, have been cultured from seals and sea lions. Many of the bacteria show antibiotic resistance, suggesting that they have been exposed to these drugs before infecting marine mammals.
The incidence of harmful algal blooms, such as those producing domoic acid, appears to be increasing in recent years. Although the reasons for this increase in toxin-producing blooms are unclear, human activities that alter terrestrial runoff and increase global warming may be important. These indirect effects may increase nutrients for phytoplankton blooms or change the types of nutrients available, which may determine whether or not the blooms become toxic. Biotoxins produced by these blooms can have dramatic effects on marine mammals, resulting in mass mortality events,
as well as less obvious effects on reproduction and physiology. Domoic acid was first detected as causing California sea lion deaths in 1998, when seizuring and dying animals were found to have eaten anchovies and sardines containing it. Since then, there have been repeated sea lion die-offs associated with exposure to this toxin, as well as abortions and death of prematurely born
pups following pregnant female sea lions' exposure to this toxin.
Other toxins detected in California sea lions include PCBs and DDTs, contaminants that accumulate up the food chain and are
regularly detected in marine mammal tissues. High PCB levels in California sea lions have been associated with an increased risk
of cancer as well as altered hormonal levels in harbor seals and
Disturbances to marine mammal health from human action are thus varied, ranging from the obvious to those requiring thorough examination and sampling of affected animals to detect. These effects will require continued monitoring as well as continued collaboration among ecosystem managers, researchers and veterinarians to understand better the relative importance of these various threats to the long-term health of the marine mammal population.
The Marine Mammal Center
|Marine Protected Areas: Gaining Attention |
Anyone who listens to the latest news on ocean issues is bound to hear about marine protected areas (MPAs), which are discussed with conviction and enthusiasm by some, wariness and disdain by others. What exactly is an MPA, who's talking about them and why the rise in conversation over this often-misunderstood subject?
"Marine protected area" is an umbrella term for a managed area in the marine environment that provides some degree of resource protection. MPAs can be established by different authorities (e.g., municipal, state) and involve a range of protection strategies. Most restrict or prohibit one or more human activities, such as disturbing or harvesting marine life, ocean dumping, oil drilling and the like. Besides having different goals or levels of protection and use, MPAs can vary dramatically in size and shape and safeguard an array of natural or cultural resources.
Related terms -- including marine park, marine preserve, marine reserve, national seashore and others -- may also be used to describe MPAs. For example, the Monterey Bay National Marine Sanctuary is a large, federally designated MPA that encompasses diverse habitats and shipwrecks off central California. To help protect the sanctuary, the National Oceanic and Atmospheric Administration (NOAA), the agency responsible for its management) conducts research, monitoring, education and outreach programs while restricting or prohibiting some recreational and commercial uses.
|Figure 1. Larger fishes produce more young, as is the case for these vermillion rockfish. (Figure courtesy of PISCO and Donna Schroeder)
A common misconception is that all MPAs are 'no-take' areas, closed to public use. But most MPAs, like the sanctuary, are managed for a variety of uses. Approximately 1 percent of the world's oceans and only .01 percent of U.S. waters are encompassed by
no-take areas. Locally, three small, no-take state reserves cover
less than .01 percent of sanctuary waters.
Scientific research has shown that properly designed MPAs -- particularly those that restrict or prohibit the removal of marine
life -- can effectively conserve a diversity of marine life and
habitats. In fact, these types of MPA generally contain a greater abundance and higher diversity of species as well as larger fishes within their boundaries than similar habitats outside the protected areas. Larger fishes often produce more young than smaller
fishes (see Figure 1), and in some cases, their young may be healthier and more likely to survive. MPAs can prevent, slow
or reverse the destruction of ocean habitats and help maintain a diversity and abundance of species.
Because pollution, overfishing and habitat destruction threaten oceans today, many groups, including governments,
scientists, fishermen, concerned citizens and others, are discussing the need for new MPAs to complement existing ocean protection measures. MPA are gaining momentum as a marine conservation tool throughout the world. Countries such as South Africa, Italy, Canada and New Zealand have all established 'no-take' marine areas. In July 2004, Australia
designated one-third of the Great Barrier Reef as one.
Recently, both the U.S. Commission
on Ocean Policy and the Pew Oceans Commission called for a new system of MPAs to support ecosystem-based ocean management in the United States. In 1999, the Marine Life Protection Act (MLPA) mandated that the State of California implement and manage an improved network of MPAs to protect marine life, habitats, ecosystems and natural heritage. Currently, the California Resources Agency and California Department of Fish and Game are partnering with others to achieve the goals of the MLPA.
In 2002, a review of the sanctuary management plan resulted
in significant public comment on this issue -- most urging the
establishment of new MPAs with restricted harvest in some areas of the sanctuary to provide for greater ecosystem protection. As a result, NOAA convened a diverse group of stakeholders to design potential new MPAs in federal waters within the sanctuary (generally beyond three nautical miles of shore) and evaluate their utility. As new MPAs are proposed and considered, their design and
location will also reflect the desire to support sustainable fisheries, since fishing is an important cultural and economic activity in
the sanctuary. Designation of new MPAs in state waters of the sanctuary (generally within three nautical miles of shore) will be accomplished through the MLPA process and the California
Fish and Game Commission. The sanctuary and MLPA staff are working closely to coordinate efforts and share resources to
design the new system of MPAs.
Not everyone agrees that new MPAs are needed, and their
potential costs -- including socioeconomic impacts to fishermen
and potential for fishing effort to shift into other areas -- should
be considered. One thing is certain, however: the discussion
about MPAs will continue as new networks are established in California, and likely, in other parts of our nation and the world. Most critical to the success of new MPAs, and all ocean protection measures for that matter, is for those who care about the ocean -- managers, fishermen, scientists, conservationists, divers, business leaders, citizens and others -- to share their knowledge and ideas and work together to help resolve environmental issues. Only
by coming together can we ensure that our oceans are healthy in
To get involved with the designation of new MPAs or submit
your comments on this matter, visit www.dfg.ca.gov/mrd/mlpa/ or www.sanctuaries.nos.noaa.gov/jointplan/.
Monterey Bay National Marine Sanctuary
|Sanctuary Volunteers Are Priceless! |
Volunteers are integral to the success of Monterey Bay National Marine Sanctuary programs. Local citizens participate in advisory groups -- such as the Sanctuary Advisory Council and its four working groups -- or in the field with the Coastal Ocean Marine Bird and Mammal Education and Research Surveys (Beach COMBERS) or as interpretive kayakers, intertidal surveyors and water monitors. The volunteers are as diverse as the jobs they implement: they range in age from 10 to 85 and include students, professionals and retired citizens. Last year, more than 500 volunteers donated 10,300 hours to sanctuary programs.
|Maris Sidenstecker and Enid Irwin measure transparency at the Snapshot Day
monitoring event. (Photo by Karen Harris)
Sanctuary volunteers are enthusiastic and can be easily trained to perform work that staff don't have time to accomplish. Our large ratio of volunteers to staff clearly demonstrates their ability to be more places more often and to collect more information throughout the sanctuary than staff could ever hope to accomplish alone. These individuals are also valuable stewards of the environment and are able to share their understanding and concern for the environment through their actions and contacts in the community.
Several sanctuary programs that monitor and protect our coastal resources would not be possible without community volunteers. These include TeamOCEAN, Beach COMBERS, LiMPETs and the Citizen Watershed Monitoring Network.
TeamOCEAN (Ocean Conservation Education Action Network), an outreach program initiated in 2000, provides face-to-face interpretation of sanctuary natural history to kayakers on the bay. Knowledgeable volunteers greet and interact with visitors on the water and promote respectful wildlife viewing by explaining how to enjoy marine wildlife without disturbing the animals' daily activities. In 2005, 48 TeamOCEAN volunteers interacted with more than 5,500 people on the water, and they have reached more than 22,000 visitors during the past four years.
Beach COMBERS, a beach survey program, relies on more
than 80 trained volunteers to achieve its goal of monitoring the status of stranded birds and mammals as an indicator of the
sanctuary's health. (See article, p. 18.) Since 1997, volunteers have collected information on stranding rates for a variety of bird and mammal species that inhabit or visit the sanctuary. Pairs of volunteers monitor more than 20 beaches throughout the sanctuary, surveying selected beach segments monthly during low tide.
LiMPETs (Long-term Monitoring Program and Experiential Training) is yet another beach monitoring and data gathering program; it is conducted primarily by high school students. In 2005, 1,390 students surveyed rocky intertidal or sandy beaches to document the population density and diversity of marine organisms living in these habitats. Data from the program can be used to assess environmental health, and the students involved gain understanding of the value of scientific monitoring and the importance of intertidal and sandy beach ecosystems.
The Monterey Bay Sanctuary Citizen Watershed Monitoring Network (Network) also relies heavily on volunteer participation. The Network partners with the Coastal Watershed Council and local cities to implement several volunteer-based water quality monitoring programs, including Snapshot Day, Urban Watch and First Flush. These programs continue to grow each year, both in geographic scope and number of participants. Last year, more
than 280 Network volunteers donated 4,075 hours.
Snapshot Day began in 2000 as a one-day event in which the majority of rivers and streams along the coast were monitored to assess the quality of the water and surrounding habitat. This event began as an educational activity and has grown into a valuable source for water quality data. In 2000, more than 120 volunteers monitored 108 sampling sites. In 2005, Snapshot Day involved 163 sampling sites throughout the sanctuary, monitored by 161 volunteers.
Urban Watch is a dry-weather monitoring program in which volunteers collect and analyze urban runoff for common urban pollutants approximately 20 times throughout the dry weather
season. Urban Watch has also grown from just one city (Monterey) in 1998 to five cities (Monterey, Pacific Grove, Capitola, Live Oak and Scotts Valley) in 2005, with the participation of 55 volunteers.
|Volunteer training and "dry run" for First Flush 2005 (Photo by Art Evjen)
First Flush has also expanded over the past five years. In this program, volunteers collect water samples during the first major storm of the season at any time of the day or night. In 2005,
83 volunteers sampled 32 storm drain outfalls in nine cities, as
compared to just 25 volunteers who sampled 14 outfalls in three cities during 2000.
Each of these programs provides information on the quality
of water flowing into the sanctuary. Results have been used to acquire grant funding for additional monitoring or to support restoration projects. Results have also been used to determine
the most appropriate management practices and educational
programs to implement. In addition, they have spawned monitoring in areas where it was warranted. For example, high
copper and zinc concentrations detected during First Flush in
a Monterey drainage led to additional upstream monitoring to attempt to track the source of metals. Further, Snapshot Day results led to a grant-funded "Clean Streams" monitoring program in two Salinas watersheds in which monitoring is attempting to determine land use impacts on the waterways that lead to the
sanctuary. In all of these programs, sanctuary staff and partners work together to address water quality issues.
No matter what activity they are involved in, volunteers are a tremendous asset to the sanctuary and its programs. An abundance of energy, enthusiasm, dedication and concern for the sanctuary make them a priceless collection.
Monterey Bay Sanctuary Citizen Watershed Monitoring Network