From Scripps Institution of Oceanography. Historical Photographs Expose Decline in Florida's Reef Fish, New Scripps Study Finds. Oceanworld
Up and Down
The photo strip above illustrates a process referred to as "fishing down the food web", indicating a trend towards catching smaller and smaller fish over time. A food chain is the sequence of who eats whom in
a biological community (ecosystem) to obtain energy or nutrition, and a network of many
food chains is referred to as a food web.
All living creatures in a food web can be categorized by whether or not they can transform inorganic matter such as carbon or sulfur dioxide into organic matter, such as sugars and starches. Primary producers, or autotrophs, use energy from the sun or other inorganic matter to create organic matter. Producers form the base of the food chain, and all other living species depend on these producers: plants, algae (such as micro-organisms such as diatoms, dinoflagellates, coccolithophores and larger algae), some bacteria and archaea. Consumers, or heterotrophs (e.g. humans and other animals) feed on producers to obtain the nutrients they need to carry on the chemical processes that allow them to grow and function.
The way food webs are conceptualized, primary producers are at the base, called the first trophic level, or level 1. At the top of food chains and webs (levels 3 though 5) are consumers, many classified as apex predators, those who eat everything below them to varying degrees and who have few if any known predators to keep them in check. Herbivores, called primary consumers, eat the primary producers, and carnivores eat the herbivores. Omnivores and higher level carnivores eat lower level species. In between and at all trophic levels are decomposers or detrivores such as bacteria and fungi, who break down dead or decaying creatures into basic elements.
Food chains and webs will be explained throughout this eating down series. For just now, the important point is the directionality: going up or coming down. Down refers to the direction from top level predators at the top of the food web, the highest trophic levels of 3 or above, towards lower and lower levels, moving toward level 1, which is that of the earth's primary producers. Down and up do not necessarily imply intelligence, who is the most evolved, who is the tastiest, or the best of anything. Using the pyramid metaphor, down is towards the base or foundation on which everything above depends. Top-level consumers such as Homo sapiens depend on species in the levels below them to supply what they need to survive.
As countries industrialize and per capita income rises, consumers tend to eat more meat and fish, that is, they tend to choose to eat those foods that provide their bodies effectively with what is needed for metabolism. World apparent per capita fish consumption has increased from an average of 9.9 kg in the 1960s 16.4 kg in 2005. The process of industrialization thus puts pressure on food industries to produce more meat and fish. Industrial agriculture and aquaculture also put another pressure especially on fish: fish are ground up for feed both for land-based animals and aquacultured marine animals.
Going Down
Fishing down happens when the fish at the top, the biggest strongest fastest smartest (best adapted) and most desirable fish, notably, apex predators such as tuna and shark, disappear. Causes include overfishing, loss of habitat, pollution, climate change, and ocean acidification. Fishing down also happens when fish populations are decimated because of greed, ignorance, and lack of foresight. In the photo strip at the top of this post, fishers display what are called trophy animals, often caught not for food but for trophy status. Tiger species have gone extinct not because of food demand but because some apex predators catch other top level predators strictly for fun and fame (more cognitively motivated than the "lower" needs of food and drink).
The most significant result of the disappearance and diminution of apex predators is that entire food webs are becoming unbalanced, which first alarms scientists, who publish their alarm mostly in scientific articles. When webs are unbalanced, systems don't function as they were evolutionarily designed to. Small un-noticeable effects occur continuously, but more importantly, catastrophically cascading events are also occurring, with outcomes that could be noticed by anyone paying even the slightest attention. When change is rapid, species lack time to adapt. Eventually, results will impact all consumers and most producers as well, meaning every living creature.
Caviar, for example, is in 2012 the most expensive food in the world, and as a direct result, many species of sturgeon are either extinct or on the brink of extinction. To show how quickly food-times change: just over 100 years ago, caviar was a free snack that was, like peanuts, heaped in bowls on bar counters to increase thirst and motivate more beer drinking.
When populations of large highly desirable fish such as Chinook salmon or cod decline to the point that a fishery is no longer commercially viable, the fishers either change vocation or start fishing for what is still available, such as smaller marine animals (e.g., whelk), less traditionally popular species such as squid, or really hard-to-make-appetizing fish such as California's new emerging fishery Hagfish. The 0 to 50 centimeter scale at the lower right-hand corner of the photo strip above indicates changes in the size of trophy fish taken on Key West charter boats; this photo strip graphically flashes in condensed form the phenomenon that big fish are becoming scarcer. Many of the most attractive food-choice fisheries such as salmon, abalone, and bluefin tuna are either now tightly regulated, closed down in many areas, or in some cases, such with sturgeon, species have already gone extinct.
Planning for the trip down
The next few posts will be about eating down the food web, a topic introduced in the post "From Bouillabaisse to Slime Eel Stew". This series will also address the prospect of planning for that which is predicted, involving several of the adaptations that have catapulted Homo sapiens to top spot in the cognitive niche.
Traits and behaviors that over evolutionary time have given a species a survival and reproductive advantage (adaptations) are often rewarded by evolution with feelings of pleasure. Pleasurable experiences are more likely to be sought out and repeated. Eating sweet, perfectly ripe fruit picked right off the tree, when nutritional value is highest, is the classic example. Sources of pleasure for those in the cognitive niche are almost infinite; almost any skillful manipulation of data is rewarded with feelings of feeling good, such as guessing right on a quiz, learning the right answer, observing that a prediction turns out as anticipated, and when planning turns out to optimize the outcome. Imagining, learning from the past, anticipating, and planning are all well-rewarded features giving humans a survival edge over polar bears and other apex predators.
After first assessing the credibility of a prediction, humans can then begin to prepare for that which is reliably predicted. This can make the trip down as good as it gets. The most useful beginning point for effective long-term planning for the descent is to understand the processes, the predictions, likely effects, remediations, and possible adjustments to the loss of the biggest and best fish. Eating down a marine food chain is a process that directly results from the slightly better known, less personally invasive concept: "fishing down the food chain". Fishing down implies eating down, and both imply radical menu changes.
Fishing down the chain/food web is, at first blush, the soft sell approach to warning, because it seems to locate the "fishing down" process primarily in the fishing industry, which has the effect of isolating the trend of disappearing apex species (e.g., tuna, barracuda, swordfish, sailfish), from mainstream consumer awareness. The functional principle is this: "I prioritize issues according to how much they affect me personally. If it doesn't affect me, it is not a top priority."
Planning Ahead, the Prequel
Below is a just-for-fun quiz for anyone who enjoys functioning in the cognitive niche. Ideally, the quiz will provoke quizzical processes about what is happening, why, whether preventative measures can still be taken, and which ones will optimize rewarding outcomes. As a rule, humans are captivated by voluntary quizzes, they learn from their errors, and celebrate their successes.Win Win.
As we eat down the food web, we will be confronting foods that have previously been considered unappetizing or commercially non-productive, such as Hagfish and whelk. As a top predator, Homo sapiens is driven not exclusively but consistently towards proteins, which are necessary for building the cells of life. A primary target within the protein drive is preferentially towards food that can be classified as optimized proteins, such as fish, some dairy, and many red meats, many of which are complete proteins, supplying essential amino acids in the right proportions as required from diet. Biologically, we are driven to acquire that which promotes our survival. Fitness kicks in as a factor when some members of specific species are driven and better equipped to acquire those foods/resources most likely to support the reproduction of the species.
Throughout history, humans have proven adaptive in the short run to hardships. An example might be WWII France, when fresh red meat was unavailable to most French citizens and many became skilled at picking out maggots from their meat so that they could still consume acceptable sources of protein (maggots were considered unacceptable sources of proteins, most probably, because they preyed on dead flesh, and dead is a lesser value.)
Contemplating Hagfish as a primary protein inevitably provokes the idea of spices to make this protein more appetizing. Hagfish, a bit like maggots, also depend on dead or dying animals. Not only that, they burrow into vulnerable animals and devour them from the inside out. Historically, Hagfish have been considered by most cultures not even a last resort for food purposes. The past, however becomes moment by moment more the past. Hagfish are now considered an emerging fishery in California.
First the quiz, then in subsequent posts for this series, more background on what it means to eat down the food web from a scientific framework. The value in the first quiz will be in increased awareness of spices that will make future, less desirable foods more appetizing, thus increasingly the likeliness of the survival of higher level consumers under hardship conditions. Increased awareness is often the basis for later informed decision-making that can actually affect the earlier issue. The answer to this quiz is at the bottom of this post.
The Quiz
As we eat our way down the food web, which of the following spices from the same plant families is likely to become the number one choice for spicing up this descent? They all look pretty much alike, but...
Plant Family
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Species
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Commonly Named Spice
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family Apiaceae.
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Coriandrum sativum
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|
 |
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Cuminum cyminum
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 family Apiaceae |
Pimpinella anisum
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Family:
Apiaceae (Umbelliferae)
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Foeniculum vulgar
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Family:
Apiaceae
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Anethum graveolens
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My personal prediction is that the spice most likely to become number one as we eat our way down the food web is cumin.
The next post will rationalize this prediction.
