| Laguna Cartagena, located in the municipality of Lajas, is the only natural freshwater lagoon of Puerto Rico. The lagoon gives refuge to many animal and plant species, some of them endemic and endangered. Agriculture in contiguous lands has caused sedimentation and eutrophication, affecting not only its hydrology but its capacity to sustain a high diversity of aquatic life. To restore the Lagoon, its actual condition was assessed based on the physical-chemical (pH, temperature, dissolved oxygen (DO), nutrients and heavy metals) and biological characteristics (aquatic insects) of two sites on the southwestern section of the I agoon.; A total of 67 insect species in 33 families were collected; 48 of them were new records for the lagoon. Insects belonged to five different orders Hemiptera, Diptera, Coleoptera, Odonata, and Ephemeroptera.; Among physical-chemical parameters measured at the lagoon, only DO and depth had significant fluctuations, meanwhile temperature and pH remained within acceptable ranges for the Puerto Rico Environmental Quality Board (PREQB). Ammonia and phosphate were 60 and 7 times, respectively, above those permitted by the PREQB. According to PREQB and EPA, reported values of heavy metal are not toxic to aquatic life. Chemical data indicate Laguna Cartagena has moderate water quality while biological data indicate the lagoon has a fair water quality. (Abstract shortened by UMI.)... |
