This week I finished up the rest of my whale code and started the invasive purple urchin code.
Kat suggested I add in an invasive species to spice up my simulation and I figured it would add in an element that would be less predictable (as compared to temperature dependent eggs) in terms of testing hypotheses about the Chinook populations.
So I did a bit of research of Purple Sea Urchins and found that their fertilization and development are somewhat dependent on temperature. Between 40F and 42F cell division does not occur at all or is slowed, so about 50% of the population dies. For this range I have about 6 urchins spawn. Between 43F and 68F (normal temps) cell division proceeds at normal speed and there are no irregularities, so about 0% of the population dies. Between 69F and 77F cell division occurs more rapidly with few irregularities, development is quicker but about 25% of the population dies. Above 77F and below 40F the temperatures are too extreme and none of the urchins survive.

Right now the urchins move at .5 and seek out and destroy kelp. Urchins can devastate kelp population because they breed yearly in large numbers and also because they destroy kelp holdfasts. I was thinking about changing the feeding behaviors for the Chinook due to this fact. I was thinking of putting in a collision counter for kelp. For example, if Chinook collides with kelp the kelp gets 1 hit counter and the Chinook gets 5 energy (kelp is not deleted) when another Chinook collides with the same kelp the kelp gets another hit counter and the Chinook gets 3 energy. I was thinking of reducing the energy per hit up until 4-5 hits where the kelp is deleted. This could be used to show gradual destruction of the kelp rather than instant destruction. I could also put in code where the hit counter reverses by 1 hit after 10-20 seconds have past to show regeneration.
Now for the Urchin feeding behaviors, rather than having hit counters and such if the urchins collides with the kelp once it gets deleted and the urchin gets some energy.