Good news, bad news: global fisheries discards are declining, but so are total catches

During fishing operations, fish are often caught that were not targeted. When the species in question are of low value, or protected, this 'by-catch' is often thrown overboard as 'discards', the retained part of the catch constituting the landings. The amounts of fish discarded are generally highly area- and gear-specific, but can be high; for example, discards in tropical shrimp trawl fisheries may be one order of magnitude higher than the retained catch. The latest analysis undertaken by the Food and Agriculture Organization of the United Nations suggests that global discards have declined in recent years, indicating that wastage is being reduced in global fisheries operations. By all accounts, reducing waste is a good thing, and hence good news. Nevertheless, if one considers this decline in discards in conjunction with the reported decline in global fisheries landings over the last decade, it becomes evident that total global fisheries catches (consisting of landings plus discards) might have declined at a substantially steeper rate than previously thought. This could be bad news, if it is indicative of declining total availability of fish. While acknowledging the high uncertainty in both discard and landings data at the global scale through time, the present observation may serve as an urgent reminder that global fisheries may be in more trouble than we thought previously.