The problem with the oceans is that you can't see what's going on down there. Foresters can count trees, birdwatchers have "life lists", but fishery managers can only weigh a catch and guesstimate the numbers. That's the fish that are landed - those and other life caught in nets or hooks disappear uncounted and unreported. "Counting" fish has been a problem since ancient times and the sea has remained a realm of mystery right up to the present. Ironically, as Callum Roberts points out in this informative study, it's those who have harvested sea life - often in immeasurable quantities, who have helped reveal something of what goes on beneath the waves.
Roberts understands the need for fishers. Sea life is a substantial form of protein, particularly when land animals are expensive or unattainable. Men have fished from shore, from coast-hugging boats and from ships drawing a wide variety of gear through the water seeking dinner for demanding thousands. Anyone casting into the nearest river or lake will describe fish as "fickle", unresponsive to the most adroitly placed lure. Ocean fishers, however, trailing extended nets or other gear have the same complaint for other reasons. Where have the fish gone? Roberts points out that human fishing of the seas has undergone three revolutions - trawl nets in the 14th Century, steam power, and deep ocean fishing in the 20th Century. Each of these revolutions was a step in finding the missing fish. Each has proven a way to exhaust the ocean's bounty in a short time. The fish have disappeared.
As he tours through time and place, the author portrays the greed and unreflecting view of fishers, government and even science. There's a great irony in this story in the person of Thomas Henry Huxley, Darwin's champion in expanding recognition of the theory of natural selection. Huxley, in a British government enquiry into how "beam trawls" affected fishing, firmly declared that stirring up the bottom with weighted nets actually brought up nutrients for the fish. Their numbers would increase from the practice, not diminish! Such was the state of knowledge of the seas only a century and a half past. Knowledge has improved but little in the ensuing time period, and what has been learned has been even more detrimental to the fish. Powerful ships, huge, heavy nets and sonar have given fishers valuable tools in locating shoals. Yet, the number of fish available is clearly diminishing. Why is that?
The chief reason is failure to understand the ecology of the seas. Counting catch methods tend to focus on single, usually prime species. The effect of removing large numbers of these is too poorly known. It has long been assumed that removing the larger individuals allows more opportunity for the younger fish to feed and breed. Is that a valid belief? In Canada, over a decade after a "moratorium" on cod fishing, the stocks have not recovered. One reason seems to be that older fish, knowing the spawning sites for their group - and each site apparently has its own group - aren't there to show the youngsters the way. Other fisheries have depleted the cod's prey species, keeping the existing fish small and resource deprived. Similar circumstances occur in other locations. The dredging of sea bottoms has turned food chain foundations into oceanic deserts. This seems particularly true around seamounts, which Roberts terms "refuelling stops" for large predator species such as tuna. In effect, present fishing methods are eliminating parts of the food chain - from bottom-feeders to the very top - which includes this reviewer and his readers, you. Modern fishing techniques also produce immense amount of "bycatch", undesired species, along with other animals such as turtles and sea birds such as the albatross. Are there solutions to prevent the elimination of many forms of ocean life and restore those links in the food chain?
Roberts' last three chapters deserve the closest study by fishers, international agencies and everybody who eats fish. The numbers he presents are appalling: three-tenths of one per cent of fish stocks estimated for only a couple of centuries ago. Species counts list one "collapse" after another, and bottom trawling has decimated huge areas. There is, however, a cure in the offing. Diving in various areas, the author has seen what can be accomplished by ocean reserves. Originally founded in some cases by researchers experimenting in selected sites, these areas were banned for fishing, in some cases actually fenced off to intruders. The rebounding of stocks, plus the time granted them to grow to substantial size, shows how effective the reserve can be. Projecting from some suggested proposals, Roberts concludes that ocean reserves be established over 30% or more of the seas. That preserved area, in collaboration with seven proposals for new fisheries management could lead to a fully sustainable recovery of fish stocks. It's a formula that requires immediate attention and implementation. Is your government strong enough to assist in this seas-saving project? [stephen a. haines - Ottawa, Canada]