Throughout the world’s oceans, hard structures such as natural reefs provide ideal marine habitats. Reefs provide hard surfaces to which plants, coral, and sponges can attach, and thereby provide food and shelter for many types of fish. Recently, workers in the fishing industry have tried to increase the amount of suitable habitat for fish by constructing artificial reefs from old metal objects and industrial materials and placing them in coastal waters. Artificial reefs have several benefits.
Many fishers believe that by giving fish more places to gather and reproduce, artificial reefs have increased the populations of some species of fish. For example, a report from one extensive artificial reef program in the Gulf of Mexico shows that the number of red snapper fish harvested in the area has increased by as much as ten times compared with harvests a century ago. The increase in the number of fish caught began after the start of the artificial reef program.
Artificial reefs can also improve the economic competitiveness of small-scale fishers. This is because small scale fishers are able to create their own private artificial reefs in secret locations only they know. Currently, small-scale fishers struggle to compete with larger cooperations because fishing grounds are limited in number and most are known to everyone. Creating fishing areas known only to the fishers who make them will help independent fishers support themselves and their local communities.
Finally, artificial reefs are a good way to recycle materials no longer needed for other purposes. Artificial reefs can be made from old cars and other objects that are otherwise difficult to dispose of. Once these materials have been cleaned to ensure that no harmful chemicals remain, they can be placed in the ocean to serve as reefs for marine life. Artificial reefs thus provide a relatively inexpensive, environmentally friendly way to reuse materials.
Now listen to part of a lecture on the topic you just read about.
Many scientists believe that artificial reefs are likely to create more problems than benefits.
First, the fact that more fish are reported as being caught near artificial reefs doesn’t necessarily mean that overall populations of fish have grown larger. Remember how reefs work? Reefs attract fish to them, right? This means that fish that once lived in more distant locations have moved to and stay near these reefs. So the higher catch numbers may simply mean that the reefs have attracted a lot of fish that once lived somewhere else. In fact, by attracting a lot of fish to a single location, artificial reefs may cause a decrease in fish populations, because they help fishers to catch so many fish that the fish cannot maintain their populations.
Second, it’s a bad idea to allow small scale fishers to create artificial reefs in secret locations and not tell other people where they are. Not knowing where the reefs are can cause all kinds of safety problems. For example, other fishers who use large nets to catch fish can get their nets caught on reefs and destroyed as a result. In shallow waters, boats might even crash into secret reefs. No. The only way artificial reefs can be made safe is to make their locations known. But when reef locations are public, small scale fishers have no competitive advantage in using those reefs.
Finally, artificial reefs can cause serious environmental damage even when harmful chemicals have been removed from them. This happened to the Osborne reef. The Osborne reef was an artificial reef made of used car tires. The tires were bound together. But when a storm came, parts of this artificial reef came loose and started crashing into the surrounding seafloor. The loose parts of the Osborne Reef, propelled by the force of the storm, caused a lot of environmental damage, harming many marine plants and animals living on the seafloor.
Summarize the points made in the lecture, being sure to explain how they challenge the specific points made in the reading passage.