Dive Dry with Dr. Bill

#329: Why We Need Marine Reserves, Part II: Successes

I ended last week's column talking about the cumulative effect of so many anglers over the past 120 years on the current state of our marine ecosystems. It is easy to point at commercial fishers as the cause of the problem, and certainly they take large numbers of fish, exceeding the annual take of recreational fishers for most species. I don't like seeing local squid harvested and exported to other countries when our waters need them as food for white sea bass and other native fish. This is a massive transfer of ecosystem biomass from our region to their stomachs. However, for some marine species like lingcod, the recreational take has surpassed that of the commercial take due to the sheer number of anglers in our ever increasing population.

With the population of southern California expected to grow further, this cannot go on forever without devastating our future. Regional fish stocks for most species continue to decline, yet the numbers targeting them continue to increase. New mechanisms besides traditional management methods are necessary. We need to ensure that healthy ecosystems are re-established and that the larger fish, usually with much higher reproductive potential, remain within these systems to enhance the recovery of their species. We need to ensure a future for anglers and non-take divers alike... not to mention the many other species that coexist with us on this planet. After all, the ecosystems themselves have intrinsic value beyond serving simply as resources for human use.

Many do not understand that the purpose of a good reserve, and networks of such reserves, is not just to protect the fish inside them. The reason we protect these fish is not just to improve the biodiversity, food supply, reproductive potential, population numbers and other elements of the ecosystem members within the reserve's boundaries. The other purpose is to ensure sufficient reproduction in these protected areas to "spillover" and increase the populations in nearby unprotected regions. This "spillover" occurs when fish eggs, larvae, juveniles and even adults leave the boundaries of the reserve and enter adjacent unprotected waters to increase stocks there. In these non-reserve areas, traditional fish management methods would be applied.

I've talked to many anglers who are skeptical about the concept of "spillover." Perhaps the best evidence I can offer are the commercial party boats and private vessels that cast their lines right outside (or even inside) the boundaries of existing "protected" areas including Catalina's Casino Point Dive Park. Vessels, especially certain mainland party boats, have often been reported doing this all along our coast. This has also been documented in many other countries, and is referred to as "fishing the line." Fortunately, due to clarification from the Harbor Master's office to the owners of the commercial vessels, this has been less of a problem recently. However, the captains of these vessels know where the fish are... and have shown they are in areas adjacent to partially or fully protected sites. What more evidence could one require? Perhaps a few dives in our dive park to see the bull bass or large male sheephead (the four "Oscars") there... now a rarity elsewhere along our coast... would add more evidence.

Some anglers state that there is no science to back this up. Well, as a marine ecologist, I'd like to suggest that they aren't reading the scientific literature on the subject, and that the fishing publications may not be offering such information to their readers. There are at least 23 nations which have established marine reserves, many dating back decades and offering good scientific data to base conclusions on. Scientists have studied and published results on at least 80 reserves world wide. Let's look at a few of them.

Back in the early 1990's I had the pleasure of meeting Dr. Bill Ballantine when he gave a talk on marine reserves at UCSB. Dr. Ballantine helped establish New Zealand's no-take Goat Island Marine Reserve in 1977 after 12 years of personal effort. Within a few years snapper and lobster densities within the reserve increased as much as 15 times. After opposing it initially, commercial lobstermen began to see much larger numbers of "crayfish" in their traps, and soon were among the staunchest defenders of the reserve, actually helping to patrol it to stop poachers. In fact lobstermen in the that country's Fiordland area pushed for the creation of 10 new marine reserves in their region. New Zealand's fishing industry itself proposed setting aside 30% of the country's waters to replenish species and habitat devastated by bottom trawling.

In 1978 the National Park Service established the Anacapa Island Ecological Reserve around that small island off Ventura. Monitoring studies over the years have demonstrated that sheephead are three times more numerous than in areas outside the reserve, and lobster are seven times more numerous. The increased population sizes obviously have an effect on the ability of these species to reproduce. Even the kelp, which provides food and structure for fish, was five times denser and persisted longer than in nearby unprotected areas. In part this was because the increased lobster and sheephead populations kept sea urchins under control (as they do in our dive park) and prevented them from decimating the kelp as so commonly occurred earlier due to overfishing of these urchin predators.

Reserves were established in the waters off Nova Scotia, on the East Coast of Canada. Although these reserves only protected 10% of the estimated lobster population, the lobster in them produced over 50% of the larvae released in the region. Thus even protecting small portions of coastline may have tremendous benefits. Many scientists suggest a minimum of 20-30% of a region's coastal habitat should be protected, and some have even gone as high as 50%. Now that's what I call the wisdom of Solomon... take the sword and cut the coastline in half!

Off Georges Bank to the south of the Gulf of Maine, fishing closures were established to protect the seriously declining stocks of overfished cod. As a side effect, within just four years there were 14 times more scallops in the protected areas, and individuals grew to larger sizes and reproduced at higher rates.

The federal government established the Merritt Island National Wildlife Refuge in the area around Cape Canaveral (Cape Kennedy today) in part as a security measure to protect the launch facilities and operations. Different species of fish there increased in abundance two to 13 times their original numbers. Of importance to anglers, fish tagged within the reserve were later recaptured outside it, once again illustrating the concept of spillover.

Let's look at another West Coast example. In 1990 the Washington State Dept. of Fish & Game established the San Juan Islands Reserves. One important commercial and recreational species studied there was the lingcod. I mentioned previously that the recreational take of these fish has now exceeded the commercial harvest. Studies of the lingcod populations established that there was two to four times the biomass (total weight) of lingcod in the protected areas than in the adjacent unprotected ones. Lingcod of reproductive age were ten times more abundant inside the reserve. Due to their larger average size, the lingcod in the reserve produced three times the number of eggs compared to those outside the reserve. As an aside, fish which were not targets of anglers such as the striped surfperch showed no significant difference in size or abundance inside the reserve.

These are just a few of the many success stories. Reserves not only help restore marine ecosystems, but also provide better fishing. If our local economy collapses, it won't be because of marine reserves... it will be because we have overfished our waters over many decades, and did not take the steps necessary to restore them for our children and grandchildren, whether they be anglers or no-take divers and snorkelers. Imagine what our waters would be like now if Holder's original 1913 Catalina reserve had survived "politics." If these recent columns have not sparkled with my usual sense of humor, it is because I look upon this as a very serious issue for the future of Catalina's appeal as a destination for visitors of many types.

© 2009 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

The MLPA proposal from Lapis Group option A: one that not only reduces existing protection for marine life,
but also the possibility to create spillover to replenish fish in adjacent areas for anglers due to the small size
and poor placement of the proposed reserves.

This document maintained by Dr. Bill Bushing.
Material and images © 2008 Star Thrower Educational Multimedia