Given the continuing debate about the inclusion of fishmeal in aquafeeds and the search for suitably sustainable replacements, I thought this site might be of interest.
While it is true that fishmeal prices have escalated dramatically in the past year or two, it is equally true that many of the potential substitutes for fishmeal (like various animal protein meals and soybean meal) have also risen, making it more difficult for researchers and aquafeed manufacturers to develop a commercially and environmentally viable alternative.
In researching price trends, I came across a blog maintained by Wayne Bacon of Hammersmith Marketing, a company specialising in sourcing protein meals for the feed industry in Africa, the Mediterranean and the Middle East. Every week, Wayne summarises the market prices for a range of meals, and comments specifically on the state of the fishmeal market.
Great (almost) real-time information – check out their November 9 2008 report

Adrian, you are right in at the moment, fish meal has definately come down in price, but so has all of the commodities in the last month. We have seen an unbelievable run up in prices driven by the food vs fuel debate, but we have regained some normality in recent weeks, well that was until the current financial crisis came inot play.
Some research out of the US, although very early and slightly deceiving, “in a blind taste test, farmers were unable to detect a significant difference between trout that were raised on plant-based food and those that were fed a convential fish-meal diet”
The plant-based diet included Clearwater barley, corn gluten meal and soy protein concentrate. Low in phytic acid, it’s been targeted specially for the commercial fish market. Researchers said low-phytate barley makes more phosphorus available to fish to absorb immediately, so less of the nutrient is excreted. So in addition to being a potentially lower-cost alternative to fish meal, low-phytate barley promises to be more environmentally friendly, they said.
I still personally believe longer term we need to find a sustainable source of alternative fish feed.