By Phil Garn, Advocate for Live Buoy Monitoring
More than twenty members of the public including the colorfully attired Dani Grady and her “Sharkbait Mamas” met with Dr. James Anderson and Graduate Student Patrick Rex from Dr. Chris Lowe’s California State University Long Beach Shark Lab team and Coronado Beach Lifeguard Captain Sean Carey during the first hour of their joint white shark tagging operations at Center Beach in front of the Main Lifeguard Tower on the morning of March 31st. More adults and their children would come by throughout the day’s tagging operation to find out more about the increased presence of white sharks in Coronado and throughout Southern California. They also learned about the white shark tagging program, white shark behavior and the benefits of a suite of four Live Buoy Monitors which could be synched with the United States Navy’s two Live Buoy Monitors [already on order] to provide the best and most sophisticated coverage in the world!
While Captain Carey and Dr. Anderson supervised operations from the shore including Patrick Rex piloting the aerial drone scout, Beach Lifeguard Sean Hogan piloted the Lifeguard Rescue Personal Watercraft with Graduate Student Brian Sterling doing the Go-pro filming to document white sharks underwater while Beach Lifeguard Damon Bassett manned the rescue inflatable with Graduate Student Jack May doing the tagging and taking biopsies. Beach Lifeguard Garison Covel went out and retrieved the monitor underwater from the [non-connected dumb] stationary buoy for downloading. The stationary buoy was re-placed on a new mooring and marked with a rescue tube. The other Beach Lifeguards watched the water, took care of stingray victims and reunited lost children with their loved ones on an extremely busy summerlike day in the midst of Spring Break. Coronado Fire Chief Jim Lydon also came by to observe the joint operations for quite some time and confer with Beach Lifeguard Captain Sean Carey.
Many of the questions were sophisticated, thoughtful and challenging. Eric Dawson asked Captain Carey, “[In addition to education and science] how could you use Real-Time data from the suite of 4 Live Buoy Monitors?” Captain Carey replied, “If I got information that there was a 10-foot shark in the area of the Central Beach Main Tower, I would not have my Junior Guards doing a buoy swim and schedule another activity [for the day.]” Dr. James Anderson explained not only would Coronado Beach Lifeguards have real time access to local buoy data from their own buoys but data collected from all the buoys that have been placed along the California Coast. This means if there was a 10-foot shark tagged up in Orange County last year, likely to be 11 feet, that was now in the vicinity of Coronado Beach, the lifeguards would be able to see this data as it was happening in Real-Time and make informed decisions. Captain Carey said this was the type of real time information that would cause the Beach Lifeguards to man up and launch their Personal Watercraft for further investigation.
Throughout the day the scientists and lifeguards observed and tagged some smaller white sharks in the five-foot range, previously the white sharks tagged and observed were over six feet and as large as eight feet long. Twelve-foot sharks had been reported in the past year by surfers, lifeguards, BUD/S instructors and Dr. Anderson documented an estimated 9-foot 5-inch white shark weighing about 450 pounds encountered by a swimmer on December 30, 2020. Dr. Anderson and Patrick Rex explained that in April they typically observe an increase in the number white sharks they observed from the previous year. They believed this was because smaller animals they had tagged were returning to the same area as well as other animals they had not tagged in addition to new pups recently born. Recall from previous local articles that when white sharks are born, they range from 3.5 to 5.5 feet. As the white sharks age, they are better able to thermoregulate and will often stay in the same area, while younger sharks tend to move south for warmer water. Dr. Anderson said they were finding some of the younger juvenile sharks (typically under 10 feet) seemed to have better thermoregulation than previously thought and were staying in the same areas throughout the colder winter months.
Another phenomenon Dr. Anderson explained was the long-term effects of monofilament fishing line and nets on local fish populations including white sharks. With the improvement of monofilament line and its rapid incorporation into fishing nets, particularly inshore drift nets, inshore gill nets and long line fishing in the 1960s, many species of fish were cleared out of local waters rather quickly. Despite prohibitions against gill net and drift net fishing in coastal waters, it took many decades for these species to come back and come back in substantial numbers. This was a surprise for younger fishermen and researchers who had never encountered the species before over the course of decades, while elders remembered the sea’s former bounty.
The Lifeguard and Shark Lab team wrapped up tagging operations about 3:00 pm then hauled the boats out for cleaning and maintenance. By that time, they had tagged two new sharks, observed two previously tagged sharks and took biopsies from three animals. Patrick Rex believed he had seen at least six separate animals during the day and most of these were just outside the surf zone, while some were just under the waves. This brings the number of tagged white sharks to seven in Coronado. The Beach Lifeguards would continue to have a very busy day until their shifts ended at sundown with an estimated beach crowd of 16,000 people and ten stingray hits on top of the joint operations. With masks and easy social distancing in the open air on the beach, this was a perfect opportunity for the public to ask the experts and find out more. There was great enthusiasm from the public who said they would share what they had learned with their friends, neighbors and Coronado City Council members about safety, education and science, encouraging the City of Coronado to obtain a suite of four Fathom, Live Buoy Monitors to cover our entire 1.7 miles of oceanfront beach. The next shark tagging will be in a few weeks depending on scheduling, drone clearance and weather and the public is welcome to attend once again.
By Phil Garn, Advocate for Live Buoy Monitoring