E. Long Term Monitoring

In one sense we really don't know how to do long term monitoring of spawning aggregations, as we do not necessarily know what is the essential information to acquire now that we will want in the future. It is, therefore, better to document as many things as possible, in a thorough, quantitative and repeatable manner, in the hopes we are doing the right things now, following clear and simple guidelines and adopting sound scientific principles. Since we are seeing a general decline in spawning aggregations worldwide (there are relatively few that are growing or recovering), we should work to gather as much baseline information as possible now.

If a firm basis for monitoring is established, then long term monitoring becomes feasible. Maps, GPS location information, other "hard" documentation is crucial. Our technology of obtaining this information may improve significantly in the future, but today we need to do the best job we can with the tools available.

Finally, we know little about the recovery of aggregations, once fished out. Protection has been applied to some areas that no longer support aggregations and we can learn some very important lessons from watching what happens to such areas. Will such areas ever recover? Once protection is in place, they will come back? In Palau, one aggregation that was possibly fished out was subsequently protected and shows signs of recovery, although too little is known of its natural, pre-fished, state to be able to evaluate the significance of the changes taking place. It is very tempting to focus just on aggregations that still appear to be in good condition but, given the very likely connectivity between reefs and possibly between aggregations, it is also important to consider the need to restore seriously depleted or even extirpated aggregations as part of the bigger picture. Therefore, the monitoring of extirpated sites is useful and important, especially in areas where the populations of aggregating species appear to be depleted and where aggregations were once substantial. It might seem like a futile exercise (the authors have all been through it many times), but the importance in the medium to long term might be great.

D. Publication of Information

It is important for scientists to get technical information out into the general scientific literature and open to peer scrutiny as a basis for sound conservation action. It is also important that some of this information is also made available to a wider public as well as to the fishing community.On the other hand, certain kinds of information, such as the specific locations of aggregations should not be released unless for the express purpose of management and conservation, to ensure that the information does not facilitate yet further uncontrolled aggregation exploitation.

To get information into the hands of practitioners, it might be more useful to make it available in video form, rather than printed documents, although brochures and posters are also very important. The video is a powerful tool and even the most remote islands, if they have a human population, almost always have a video system for watching movies.

B. Archiving of Information

It is important to be able to archive and consolidate information concerning reef fish spawning aggregations. This can include anecdotal information and observations, "hard" data from catches from aggregations, photographs, film and video footage, and other types of information.

The Society for the Conservation of Reef Fish Aggregations has a database on reef fish aggregations world-wide and intends to serve as a repository for other types of information. In connection with the overall database, certain criteria have been established that observations must meet before a given aggregation of fish is included in the database as a spawning aggregation (see Section II.C). The intention of these criteria is not to exclude information, but rather to put confirmed and tentative information into different tables, so that what is confidently known is not confused with the tentative and unconfirmed. If an observation does not meet these criteria, it is still possible to include the observation as "probable", "possible" or some other relative estimation of the confidence associated with the observations or data, and efforts can later be made to confirm or otherwise such reports. The instructions for making additions to the SCRFA database are available on the SCRFA website (www.scrfa.org).


Figure 57. A Live Reef Fish Trade vessel, photographed in North Male Atoll lagoon, Maldive Islands. Copious water pours from the tanks inside the vessel, indicative of the amount of effort required to keep its large cargo of reef fish alive prior to steaming to a distant port such as Hong Kong (PLC)

Figure 58. Live reef fishes, mostly parrotfishes and small groupers in a streetside aquarium in Hong Kong (PLC)

C. Conservation of Spawning Aggregations

Does Protection of Aggregations Help?

In a number of places, various types of protection have been put in place to conserve aggregations. Do they help and what means can be utilized to show that they help? While it is not within the scope of the present manual to cover these protections in detail, we would like to comment on the types of protection put into place in some areas. Protection can include a prohibition of fishing in a given site, usually the aggregation area and nearby reefs, and protection of species by closed seasons during the spawning period. A combination of both types of restrictions seems most likely to have a positive effect and has been implemented in several places. The former seems the most obvious when fish(es) at certain sites are rapidly being wiped out. Closed seasons are particularly relevant where aggregations can not be patrolled or site protection readily enforced. The latter type of regulation covers aggregations that are unknown to anyone, except perhaps a few fishermen, but may have great importance in reproductive success.

Various methods can be used to prevent overexploitation of aggregations. Johannes and Kile (2001) recommended banning the catching and holding of live groupers (for the live reef fish trade) during the months of spawning aggregations, instead of trying to protect the aggregation sites which are widely dispersed and far from settlements. The type of protection implemented depends on the local social and cultural contexts as well as species and fishery conditions involved (Domeier et al, 2002). Presently the most widely applied approaches to protecting aggregating fishes are seasonal (no fishing and/or no commercial sale of the species during the spawning season) or spatial (the spawning site itself is protected during the aggregation period or is incorporated into a marine protected area).

Figure 59. These fishermen in the Cayman Islands have made a good catch of Nassau groupers from the spawning aggregation, but how long will this last. This photo was taken in 1977, a time of no regulation of the spawning site and declining catches. In earlier years, many more fish were caught, but those days were already gone. At present the fishery is closely regulated, but catches have yet to improve.

There are some signs that protection can result in increased fish size when nonaggregated populations are still fished. Beets and Friedlander (1999) documented a case where declining catch and size, plus a highly skewed sex ratio (in favor of females) among red hind, E. guttatus, in the U.S. Virgin Islands reversed after protection was put in place. They reported an increase from 295 mm SL to 395 mm SL for red hind after seven years of spawning site closure to fishing, while the sex ratio change from 1:15 males to females to 1:4.

The protection of aggregation sites also tends to provide some protection for spawning segments of other species of fishes. Johannes (1998) says that "more than 40 species of reef fish spawn at the three aggregation sites" of groupers he studied. The spawning of these additional species is not limited to the grouper aggregation site, but protection of a site, as opposed to a species, means that other fishes derive secondary protection.

Fostering (the right type of) Protection

Many instances of disappearances of spawning aggregations are known (Sadovy and Domeier, in prep). In most cases fishers of a given aggregation have been aware of the declines leading to the extirpation. Sometimes the loss is rationalized by saying the fish have moved elsewhere or were disturbed and don't come anymore. While these are possible, most likely the aggregation has been fished out and most fishermen know it. In many cases, calls for protection come from those who suffer most from the loss, the fishers themselves. This is particularly true of older fishermen, who have a longer experience and have more likely seen an aggregation fishery in its prime.

In the last decade, the importance of spawning aggregations to fishery success and the level of exploitation in many areas have raised awareness, at least among monitoring agencies, of the importance of spawning aggregations in many species used for human food. Awareness needs to be raised at the level of government and the individual fisher. Without the support of fishers, it is considerably more difficult for government to put in place the controls needed to prevent loss of aggregations and ultimate decline of the fishery.

To encourage protection, communities need to identify with local aggregation sites as "theirs" and something to protect for their own sake. Certainly any community fishing the area where fishes are drawn from to spawn at the aggregation has a stake in the future of that aggregation. This is why tagging studies can be particularly important for making people realize that the fate of the aggregation affects both their short-term ability to catch fish (none will be left if the entire aggregation is fished out) and the long-term health of the fishery of the aggregating species. Such studies are also important to illustrate how far fish can move and that over-fishing an aggregation in one community can affect catches in the non-reproductive season in a distant community.

Spawning aggregations within marine parks have potential value added components. Ruitenbeek (2001) reported that the value of spawning aggregations within the Komodo National Park, Indonesia was roughly $600,000 USD at 100% protection, a level similar to the direct recreational value of the park, famous for the Komodo dragon. Sala et al. (2001) determined that dive tourism on aggregations in Belize could be worth 20 times the value of extracted fish. However, care is needed before blindly converting an aggregation into a tourist attraction in case uncontrolled disturbance should have a negative impact on reproduction or tourist dollars bypass local communities. Studies can be conducted to determine such potential impacts.

Figure 60. Groupers such as this marbled grouper, Dermatolepis inermis, from the Florida Keys are often thought to be rare, because they are seldom seen. They may just occur in an environment that is seldom fished or visited by divers, but they may also have had their populations driven down by fishing pressure. Determining such things is one of the hardest aspects of working on species of fishes that aggregate to spawn.

It is also essential to look at fisheries of those species that aggregate in their entirety and not to solely focus on the aggregation. In many cases fishing pressure occurs on both aggregated and non-aggregated individuals, both of which may be important to consider when examining population status and determining appropriate management.For example, managing an aggregation of a species that is also heavily fished at other times may ultimately contribute little to the overall problem of over-fishing of the species. As just one possible example, in Palau, aggregations of Plectropomus and Epinephelus were found to be predominantly males, to the point that any females in the aggregation were continuously harrassed by the many males (Johannes et al., 1999). This may have disrupted spawning, although the spawning behavior of the species involved is not well known. The question also arises over how such a distorted sex ratio could occur. Johannes et al. (1999) did not have an explanation for this, but speculated perhaps that this might have resulted from heavy fishing of females at non-aggregated times in more built-up, and therefore, more heavily exploited areas. This emphasizes a point that is often not explicitly considered: that changes to aggregation numbers, sexes and fish sizes at aggregations could also result from non-aggregation fishing pressure. This means that the entire fishery often needs to be considered for management, research or other interventions.

Education Issues

Although historical data on aggregation status is critically important for understanding the effects of targeting these gatherings, video is one of the most powerful ways to convey the message of the fragility of spawning aggregations today. Videos could include interviews with fishermen telling of their experiences, particularly older fishermen who are likely to have seen many changes in their lifetime. Video should have underwater and spawning footage if at all possible since most fishermen have probably never seen aggregations underwater and are unlikely to have witnessed spawning. It is, of course, important to explain scientific work in a simple manner but everybody understands the reproductive imperative and so spawning aggregations represent an excellent opportunity to teach of the importance of allowing fish to reproduce to replenish their kind.

A second video might be prepared to assist fishermen or divers who want to help on a project. One of us (PLC) previously used a video showing people how to remove gonads and otoliths for grouper work in the Gulf of Mexico.

Sociological Issues

Support from fishers is of the utmost importance to the long-term success of protecting aggregations. It is important to communicate the results of studies on aggregations to the fishers involved. This is usually not easily done, but when it can be shown clearly that aggregations are of benefit to retaining local populations, this may drive home the message that is in the fishers own best interests to conserve the aggregation.

F. Concluding Comments

If we really want to set up global long-term monitoring of aggregations, it is going to be necessary to continue the "discovery component" of aggregation work at as fast a rate as possible. At present there are only a handful of sites that could even remotely be considered as adequately quantified to serve as true long-term monitoring sites. We need to be establishing such sites now, and many of the sites needed are not yet even known to scientists or managers. The sites that are known need to be studied and quantified in more, and in sufficient, detail, one of the major reasons we have gone to the trouble of writing this manual.