Quite frankly raw peas aren't overly good for a fish. I'm sure that will come as a shock to many people but peas contain a significant amount of anti-nutritional matter and require processing to reduce those substances.
While the thesis written below contains a few mistakes (hopefully her prof spotted them) it does contain very accurate information with regards to peas, and other other food stuffs derived from plant matter. (soybeans, etc)
http://library2.usask.ca/theses/available/etd-03012005-103831/unrestricted/TracyBorgesonThesis.pdf
It's a long read, but if you start on page 34,
2.4.1.1 Antinutritional Factors it should help drive my point home with regards to feeding peas on a regular basis.
Even Canadian peas (Pisum sativum) which are white flowered varieties, produce some tannins and other anti-nutritional factors. (although far less than many other varities of peas) All it takes is a cold spell, or a dry spell, and the levels of anti-nutritional matter found in terrestrial plant matter can be pushed up drastically.
More here:
http://www.fao.org/docrep/003/t0700e/T0700E06.htm
The presence of endogenous anti-nutritional factors within plant feedstuffs is believed to be the largest single factor limiting their use within compounded animal and fish feeds at high dietary levels. Table 11 summarizes the major groups of anti-nutritional factors present in plant feedstuffs with more specific examples given in Table 12. Although these factors vary in their individual toxicity to fish, a large proportion of them can be destroyed or inactivated by heat treatment processes (Tacon & Jackson, 1985).
Unfortunately toxicological studies have not been performed on the majority of these anti-nutritional factors; on a general basis however their presence in untreated foodstuffs normally results in anorexia, reduced growth and poor feed efficiency when used at high dietary concentrations. For review see NRC (1983), Hendricks & Bailey (1989) and Lovell (1989).
Run those same peas, soybeans etc through the high temps of an extruder, and the antinutritional factors are reduced greatly, and in some cases removed entirely.
But as far as fresh peas go, organic or not, I would personally advise against feeding more than a few here & there.
