“The Ocean of Life: The fate of Man and the Sea” by the marine biologist and oceanographer Callum Roberts takes a hard look at different problems the oceans are facing today and what can be done to stop them. From overfishing and pollution (of different kinds) to something i hadn’t heard was a problem in the oceans, noise, the detail of his analysis and explanations make the the book worth reading. More, when dealing with the topic of environment people can often be tempted to view humans as an inherent problem and to that extent propose radical changes like undermining the industrial revolution as “solutions”. Instead he takes the attitude that men were meant to live in harmony with our environment and that doing so makes life better for ourselves as well, and to this end offers simple suggestions where such are available (such as switching from two-cycle engines to four-cycle engines) and explores the pros and cons of the more complicated approaches (aquaculture evidently has drawbacks) as well.
Here are 12 things I learned from “The Ocean of Life”
1) Ocean fishing has depopulated the oceans by at least 95%. Normalizing by equipment, it’s 17 times harder to catch fish now than in 1895.
One of the problems that has happened with overfishing is that as the number of fish decreases, each new generation acclimates to it as the new normal. Ancient texts about fishing describe techniques (such as sticking a bunch of spears and other sharp metal objects to a log, and letting their weight drop the log onto the sea floor on the off chance it stabs something) that would only make sense in an ocean vastly more populous than today. In the late 1800’s/early 1900’s some fisheries kept a rough tally of how many boats brought in how many fish. The oceans are much more sparse, but our technology got better. I will say, the way the author described the attempt to normalize by the improvement in our technology sounded a bit like guesswork.
2) Plastics are stable chemically as they crumble physically.
Since plastics didn’t exist until the 1950’s, there aren’t any creatures that evolved to decompose them. Plastics at various sizes can look like food for various fish. For instance, turtles will see plastic bags as jellyfish and actively seek them out and eat them. A whale was caught with the entrance to its intestines blocked off by plastic. Over time this crumbling leads to a soup of plastic. Imagine swimming in that the next time you think about littering.
3) Large fish are better for breeding than smaller fish.
While on the one hand you may imagine smaller fish as younger, and if fish aged like humans, size would not reflect increased fertility. However, larger fish have more eggs they can release at any one time, and more metabolic reserves to dedicate to the production of sperm and eggs. Smaller fish are too busy growing. This is unfortunate within the terms of minimum size laws, as those encourage fishers to catch only the most fertile of any species.
4) Most invasive species are carried by ballast. Offshore dumping of ballast can help with that.
While there are stories of invasive species starting off in someone’s aquarium, the ballast of large ships can hold enormous amounts of water, and it can be quite easy for stowaways to slip in in the form of fish larvae, or in the case of the largest ships, full size fish. Dumping offshore increases the chance that the small larvae fish will starve, being far from reefs and shallow sources of food.
5) When the ocean was quiet, whales could signal to each other from 600 miles away. Now it’s too loud.
Sound travels in water far more effectively than light, which is why dolphins bother to echolocate when they could just look at you. It’s for similar reasons that ships use sonar, which unfortunately is like standing next to a plane taking off. Also, the noise made in popular shipping lanes pretty much prevents whales from communicating across that channel. Take that, whales, we sing louder!
6) One problem with aquaculture is that ocean fishing is required to get the small fish to feed the fish that you’re farming.
This is one of the differences / problems with farming fish rather than farming animals. For each layer up the food chain, assume a multiple between 2 and 10 (depending on the ecosystem) in terms of the amount plant life required to sustain that food. For cows, it take many pounds of grain to produce one pound of meat, but the advantage is we stopped at that one level. The fish that people like are large apex predators, which feed on smaller fish, which often feed on still smaller fish, which devour photosynthetic plankton. The extra layers multiplies the inefficiency. One thing the author didn’t mention, but that many researchers are exploring and that I would like to someday when I get a house, is to set up a bug farm to feed the fish. We can feed bugs garbage without much problem, and this would have the added benefit of avoiding mercury poisoning of your favourite tilapia.
7) Corals are very sensitive to temperature changes, and even more sensitive to pH changes.
One thing I didn’t know is that coral as we know it is a symbiote of two distinct organisms, the first being an animal in the Cnidarian family, closely related to sea anemones, but the second being photosynthetic bacteria, which are responsible for the reef’s vibrant color. Many of the reefs that we have are currently turning chalk white as the bacteria die from the pH and temperature changes. Some oceanographers speculate that by 2100, if CO2 emissions continue as they are, the oceans will become so acidic that the skeletons of reefs will begin to dissolve back into the ocean.
8) It doesn’t take that long for pollution dumped in China to reach U.S. waters, and vice versa.
There was an experiment done where thousands of rubber ducks were dropped into the ocean and tracked. In a few weeks they had already appeared on some foreign shores. Based on those experiments it would be a matter of weeks or months before some appeared in China’s waters. If I recall correctly there was also a study done on other kinds of pollution, like an oil spill. When it happens in China, it’s only a few weeks before the chemical profile of the U.S. coast changes noticably. This of course does not include air pollution that can get rained onto the ocean thousands of miles away. It’s a small world after all.
9) There are tons of viruses in the water.
In any gallon of sea water there’s at least a trillion viruses. Fun fact, in additon to infecting people, viruses have been used as ways for bacteria to pass genetic information back and forth with each other. Since the single-celled organisms don’t have sexual reproduction, they’ve had to get creative. One side effect of this is that shipping and bilge water makes it very easy to pass diseases from port to port, making life very difficult for the fish. This long range travel of viruses isn’t entirely new, though. Sand and dust from Africa’s deserts has long been carried by the trade winds and tropical storms to the Caribbean, adding African microbes to the ocean and also depositing a distinct kind of sediment on the sea floor.
10) George W. Bush set aside a huge amount of ocean territory for conservation near the end of his term.
According to the book George W. is perhaps the single greatest conservationist ever, in terms of land mass. Especially if you consider that his act prompted several other nations to set aside large reserves of territory for conservation as well.
11) Humans have a fat distribution more like aquatic creatures, such as dolphins, than our ape brethren.
There is some solid evidence to suggest that we evolved as partially aquatic mammals, and that gathering shellfish provided our brains with the extra Omega-3 fatty acids that we need to grow. The upside of this is thaw we look prettier and not like chimpanzees. The downside of this is we are also likely to be similarly affected by the toxins (like mercury poisoning) that affect dolphins. One scary thing about mercury is it slowly accumulates in fat over the course of your life … in males. In females it then starts like that, then suddenly drops precipitously, and then goes up and down several times like a wave. If you haven’t already guessed why, it’s going into the kids.
12) The biggest fighter of pollution could be the clams and filter feeders.
Apparently they’re great at filtering out pollutants. Unfortunately, humans have fished out most of them. This is one of the things that makes the state of the oceans such a multifaceted problem. Pollution weakens the immune system of fish, which makes them more vulnerable to infections. Invasive species might have a harder time getting a foothold in a new place if there were more native competition. And now overfishing makes the pollution worse. On the bright side, a solid effort to improve any one domain stands to improve the others.
13) The oceans are looking at a gelatinous future.
Many of the problems discussed give an edge to jellyfish. Pollution from agricultural runoff (such as in the gulf of Mexico) creates vast algae blooms and simultaneously kills off most of the fish by enveloping them in an oxygen-free dead zone? No problem! To the jellies that algae is extra food. They are vastly better at handling low-oxygen conditions than other fish, and all the predators that would eat them are now dead. This has already been seen in the china sea and the see off of japan, where the abundance of jellies is so great that it’s difficult for a fisherman to net a bunch of fish without also getting a bunch of jellies, and having to watch the fish they just caught be poisoned by the jelly’s venom.
14) The deep Ocean and the surface don’t mix much.
The deep ocean is colder, denser and has a different salt content than the surface. Instead of ordinary mixing, as you would expect, they kind of separate. There are a few locations (usually near the poles) in the world where water wells up and joins the surface current, carrying nutrients with it. As a consequence, the deep ocean also has a current that runs opposite to the gulf stream. This reminds me of a video where Patrick Moore argued that global warming is not a problem, in that while the earth has warmed, for the last 20 years the temperature has been relatively flat, as well as a rebuttal arguing that the 1990’s and early 2000’s saw a rare series ofand events that caused deep ocean to absorb much of the heat from the surface ocean, lowering the average across those years. I’m still not sure who’s right in that debate, but it’s definitely worth looking into.
Anyway, this was a very good book and I highly recommend it.