OKay, call me picky, but former fish biologist who used to study ocean fish for a living.
First, your last comment... that the open ocean is very differant from a reef, etc is quite true. John seems to be mostly centering on a generalized mid-trophic/continental shelf region. Not "open ocean" (where light never sees the bottom) and not reef (where you have structure and light generally penetrates all the way).
For that region, I have to make a couple of corrections/clarifications
porkenbeans wrote:John, I am following what you are saying, I think.
Your TLs' are a tad inaccurate though. Here is the basic rundown of the food chain from the bottom up.
What you call "the composition layer" is in fact all the microscopic creatures that feed off of one another and floating bits of organic matter. Included are Plankton and krill mostly..
Clarification. This is really 3 differant groups. You actually have a mini ecosystem or "food chain" at the microscopic and just above microscopic (we can see them, but they are small) level
Phytoplankton are the bottom, they absorb sunlight. Also at the base is detritus (the general term for all decomposing/accumulated "matter". Zooplankton generally eat phytoplankton and detritus.. Larger zoo plankton eat smaller zooplankton, phytoplankton and detritus. Fish larvae generally eat either phytoplankton or zooplankton or detritus.
"composition zone" is actually a term used, though it is one of those things that is not universally recognized (note-- few things to do with fish are. If you want the US official terms, consult American Fisheries society or NationaL Marine Fisheries Service). Essentially what it refers to is that this is the "building" layer, that these animals convert sunlight to useable fuel.
porkenbeans wrote:Next you have the filter feeders that feed mainly off of these creatures. They include many animals small and large. Most are small, and consist of mostly invertebrates, coral, and anemones,
These also include baleen whales and many fish.
A term I learned, though it may be out of date (I will check if you wish to be that technical), is secondary predators or simply the next layer of the food web.
porkenbeans wrote:
Then comes the scavengers. Most are filter feeders, but are mobile, and can attack small prey on occasion. Included are crustaceans, such as crabs and lobsters, also starfish and slugs. this group are the "janitors of the sea" as they clean up the place.
Scavengers may be filter feeders, but the two are separate terms. Filter feeders eat largely living matter from the water column. Scavengers specifically eat the dead/dying stuff. These include many fish, too.
This is really a side chain to the above, not a next layer. That is, there is one group that ultimately arises from things the sun and another that more or less arises from dead stuff. (and a third.. the chemical energy absorbers, but they can be left out here)
These include many fish, too.
porkenbeans wrote:Next we have the predators, that attack and eat the janitors. Included are a myriad of creatures that feed off of each other and the scavengers as well. Included are just about everything that swims, but mainly fish such as the Grouper, and all fish with relatively large mouths.
Predators eat from all levels of the column. The distinction is not so much what they eat, but how they obtain it. If they eat living prey, they are predators. If they wait for it to die, they are scavengers. If they sift it out of the water column, they are filter feeders. The terms overlap and include many invertebrates and vertebrates.
porkenbeans wrote:
The top predators keep the previous group in check, and assure that a balance is maintained.
This is essentially true, but again.. "predators" really covers many levels in the food chain.
porkenbeans wrote:This ecosystem is a very complicated process, and a lot of animals are not so easy to categorize. Take the rays and whale shark, (which are in fact part of the shark family). They only eat plankton and krill. They are filter feeders. But lobsters do not attack and eat them, even though they are in the group above them on the food chain.
This is why it is a "food web" in any modern textbooks and not a "food chain".
porkenbeans wrote:For this reason I do not think that you need to worry so much about who actually eats whom. It is sufficient enough to just have the main categories represented.
1.) plankton.
2.) Filter-Feeders.
3.) Scavengers
4.) Predators.
5.) Top predators.
Also I do not think that you need to have an equal amount of creatures from each category. This scenario results in "The Build Game". It is better to have to fight for the Chain. Not having enough to go around, assures this.
To a point, I agree. I don't think you need to be too picky about what goes where. I completely disagree with the categories you have here, but again, accuracy is not necessarily critical, though, if you wish to be accurate, it is not difficult.
As for the numbers, it is actually good to have more at the lower levels.
One thing to consider is that the ocean is really a series of trophic levels. EACH level has its own set of base species, next level predators, etc.
porkenbeans wrote:If you want to make this map about the open sea, you are entering a whole different world of deep sea creatures. most live there lives in waters that light does not reach. This is almost an entirely different ecosystem.
For this reason I would like to suggest that we consider a map pack. There are creatures unique to certain regions of the world, so we could have numerous maps that represent these unique places. All we have to do is work out the basic categories, or TLs'. And the rest is just producing the images.
The differant ecosystem is prefectly true, but for that reason you might not want to just use the same format. It can get repetetive to play exactly the same maps with only minor variations over and over. I know nothing about map creation, but it seems like using some of your ideas above would be fun... bombardments, remote attacks, etc. You could even have one that involved pollution.
If you need any technical help on fish/ocean specifics or even just good places to get that information (having "vetted" several), let me know.
The San Fransisco map comes to mind. The internal texture is faded in a clear attempt to hide the fact that it IS a satellite photo. Even the maps that do not use the internal texture began on google earth, or someone elses map. 
