Seminole Tribe of Florida

This study investigated variations m body condition of brown hoplos
(Hoplosternum littorale) refuging in ponds in the Big Cypress region of southern Florida.
During the dry season environmental parameters fluctuated, water depth and dissolved
oxygen decreased, while temperature and conductivity increased. Standard lengths and
wet weights of 675 juvenile brown hoplos were measured from seven populations. Body
condition was compared between populations and through time (early vs. late dry season)
using length-weight relationship and Fulton's condition factor. The only significant
spatia-temporal variations in body condition occurred in the deepest refuges. One
population demonstrated an unexpected positive change in body condition, while another
(a deep culvert pond) showed negative changes in body condition over time. Smaller fish
(≤S65mmSL) found in these deep-water refuges demonstrated the most change in body
condition. Almost all populations exhibited isometric growth but the culvert pond
population had variable regression slopes (slopes ≠ 3 for both samples).

The Big Cypress Swamp and the Everglades of South Florida are inherently oligotrophic ecosystems that in recent decades have been subjected to increasing agricultural nutrient inputs. While extensive research regarding deleterious effects of nutrient impacts has been conducted in the phosphorus-deficient Everglades, there is a lack of research in Big Cypress Swamp. This 12-month field study assessed the responsiveness of Taxodium distichum, Fraxinus caroliniana, and herbaceous vegetation to increased nutrient levels in Big Cypress Swamp. Six nutrient treatments (Control, N, P, K, 2K, and PxK) were applied to the soil surrounding these trees. F. caroliniana had higher photosynthetic rates with 2K treatments and higher growth rates with PxK treatments. T. distichum had higher Leaf Area Index in the P and PxK treatment but did not exhibit other responses to treatment. Herbaceous vegetation showed little response to treatments. This study concluded that potassium may be co-limiting in this ecosystem.