Harbor Seal Dilemma

CMBC students comment on controversial local issue

Sealing their fate: The harbor seal dilemma at

Children's Pool beach in La Jolla, California

Matt Forrest, Ryan Wulff, Steve Chapple, and Hiro Yokoyama

A colony of over 100 harbor seals (Phoca vitulina richardsi) has occupied the beach of the Children's Pool in La Jolla for the past two decades. This colony has become a popular tourist attraction and is regarded as an educational opportunity for local schools. Although marine mammals are protected by law, some people object to the recent intrusion of the seals into Children's Pool, which was formed in 1931 when a seawall was built around a natural cove to protect bathers, primarily children learning to swim, from the crashing waves. Proponents for removing the seals argue their presence heightens risks to human bathers through the possibility of attack and exposure to fecal-contaminated water. The seals have been receiving varying degrees of protection over the years, primarily by volunteer docents. Recently, a local swimmer filed a lawsuit demanding that the City return the pool to its original state. In August 2005, a Superior Court judge ruled that the City of San Diego must dredge sand from the beach within six months. It is presumed that dredging would have the effect of lessening the level of fecal contamination, attributed to the seals, in the pool water and thus re-opening the beach for use by humans. Advocates of the dredging also believe that it may reduce the number of seals using the beach. This decision has been appealed by the City, and as of this writing, it is unclear whether the dredging will take place.

In 1999, the City of San Diego rejected a similar dredging proposal as an effective way to deal with the seal dilemma. It deemed dredging as pointless because the evidence suggested that it would not rid the beach of the seals, nor lower the fecal contamination problems in the Children's Pool. Although the 2005 court decision now mandates dredging, we agree with the City's 1999 opinion that it is unlikely to succeed. We feel that dredging is ill advised for several reasons. First, the seawall is a barrier to longshore beach sand transport and, over the years, sand carried from the adjacent beaches was deposited behind the seawall where it formed a steep, wide beach. According to Dr. Douglas Inman, a coastal erosion expert at the Scripps Institution of Oceanography, the sand on the Children's Pool Beach is now an integral part of the sand budget for the for the Boomer Beach-Children's Pool area; if it is removed by dredging, it will ultimately be replaced by sand scoured from nearby beaches, such as Boomer Beach and Shell Beach. Because beach sand diminishes the effects of wave action, beaches experiencing additional sand removal will have a greater potential for local cliff erosion. It is also likely that these other beaches will be partially, or completely, denuded of their sand, which may result in the loss of two popular beach destinations. Second, it is unlikely that dredging will improve the fecal contamination problem, because it is questionable whether it will enhance water circulation. In fact, a report by the engineers hired by the City to perform the dredging concluded that this action could actually worsen the fecal contamination problem if the seals remain. Third, because biological studies show that harbor seals have a high fidelity to the sites where they congregate, and particularly where they were born, it seems unlikely that dredging would reduce the number of seals occupying Children's Pool Beach. It is also worth noting that the presence of sand is not a prerequisite for hauling out, and that many harbor seal rookeries occur on rocks.

The situation with the seals at the Children's Pool Beach has evoked strong and contentious feelings and actions. While those for and against the seal presence both make legitimate arguments, emotion has played a larger role than science in determining the possible actions that should be taken. It is debatable whether it was a good idea to let the harbor seals establish a rookery at the Children's Pool Beach. However, the fact remains that the seals that were born there will almost certainly return, and that dredging the area and removing sand is not likely to affect their numbers nor alleviate the water quality issues. Our opinion is that the most sensible course of action is to abandon the dredging proposal, and to institute a seasonal joint use plan for the area. A removable rope barrier would be erected to protect the seals during the pupping season (January - June), and people would be allowed to swim and recreate there the rest of the year at their own risk. We also suggest that a full time ranger should be stationed at the Children's Pool Beach in order to provide educational information and to alleviate the many negative interactions that occur--between people and seals, but primarily between the diametrically opposed factions of seal supporters and detractors. Although this may appear to be a rather expensive proposition, the estimated cost of the entire dredging proposal is $500,000, and part of this money was actually set aside to hire a ranger. Because all available evidence suggests that the dredging will not result in improving the situation, we feel that a seasonal joint use plan overseen by a trained ranger offers the best possible solution to the harbor seal dilemma, and the best prospects for future harmony at the Children's Pool Beach.

***This report reflects the opinions of the CMBC students and not necessarily those of CMBC.***

The students:
Matt Forrest is a CMBC IGERT Associate

Ryan Wulff, Steve Chapple, and Hiro Yokoyama are students in CMBC's MAS program.

For updates on the issue and other opinions:
Lecky, James H. Report from Marine Mammal Workshop. Whose Beach is it Anyway? download pdf

San Diego Coastkeeper
Sign on San Diego
La Jolla Friends of the Seal

For more information on coastal erosion:
Coastal Bluffs Provide More Sand to California Beaches than Previously Believed

Photo credit: (Child) Kenneth & Gabrielle Adelman - adelman@adelman.com

Photo credit: (Tourists) Roni Galgano/Union Tribune