Detrimental conditions affecting Xestospongia muta across shallow and mesophotic coral reefs off the southwest coast of Puerto Rico.

Sponges are fundamental components of coral reef communities and, unfortunately, like other major benthic members, they too have been impacted by epizootic and panzootic events. We report on the prevalence of disease-like conditions affecting populations of the giant barrel sponge Xestospongia muta across shallow and mesophotic coral reefs off La Parguera Natural Reserve (LPNR) and Mona Island Marine Reserve (MIMR) in Puerto Rico. Four different conditions affecting X. muta were observed during our surveys, of which 3 have been previously reported: cyclic spotted bleaching (CSB; apparently non-lethal), Xestospongia-tissue wasting disease (X-TWD; apparently lethal), and sponge orange band disease (SOB; sparsely associated with X-TWD infected individuals). Additionally, we describe a fourth condition, Xestospongia-tissue hardening condition (X-THC), a previously unreported disease recently observed along the insular shelf margin off LPNR and MIMR. Within LPNR, a total of 764 specimens of X. muta were inspected and measured. Of these, 590 sponges (72.2%) had CSB, 25 (3.27%) had signs of X-TWD, 7 (0.92%) had SOB, and the remaining 142 (18.6%) were apparently healthy. Three colonies inhabiting upper mesophotic depths on the LPNR insular shelf showed signs of CSB and X-TWD. At MIMR, video-transect surveys revealed a total of 514 colonies, of which 40 (7.78%) had signs of CSB and/or XTWD, 14 (2.72%) were affected by X-THC, while the remaining 460 (89.5%) showed no external signs of disease and appeared healthy. The presence of 4 concomitant disease-like conditions in barrel sponges of Puerto Rico is alarming, and indicative of the deteriorating status of Caribbean coral reefs.

Natural phillipsite as a matrix for a slow-release formulation of oxamyl.

The performance of phillipsite as a matrix for slow-release formulation of oxamyl [N,N-dimethyl-2-methylcarbamoyl-oxymino-2-(methylthio)acetamide] was tested. The adsorption kinetics followed a first-order law, and the adsorption isotherm fitted well in a two-surface Langmuir model, suggesting a double mechanism of interaction between oxamyl and the sorbent. The sorption mechanism, studied by FTIR, provided two fractions of oxamyl. The first one is sorbed on the mineral surface, linked by H-bonding, and the second one is constituted by a multilayer of oxamyl molecules linked by a water bridge between them. The release kinetics of oxamyl from a substratum zeolite-oxamyl also follows a first-order law, with two stages that correspond to both fractions of oxamyl previously detected.

The lizard Gallotia galloti as a bioindicator of organophosphorus contamination in the Canary Islands.

The aim of this study is to propose a bioindicator organism, the lizard Gallotia galloti, and a nondestructive biomarker assay, utilising serum butyrylcholinesterase, for the assessment of the toxicological impact of organophosphorus (OP) insecticides in the Canary Islands. Laboratory and field studies were performed using the OP insecticide Trichlorphon. In the laboratory study, experimental groups of Gallotia galloti were treated with 5, 50 and 100 mg/kg of Trichlorphon, respectively, and after 24 h the following enzyme activities were assayed: brain acetylcholinesterase (AChE), serum butyrylcholinesterase (BChE), microsomal carboxylesterase (CbE) and microsomal 7-ethoxyresorufin dealkylation (EROD). BChE activity was monitored in two groups of lizards treated with 50 and 100 mg/kg of Trichlorphon, respectively, for a period of 21 and 31 days after treatment. In the field study, BChE activity was detected in Gallotia galloti specimens, 24 and 48 h after treatment of an experimental area with 10 kg/ha of Dipterex sp80 (80% Trichlorphon). Three conclusions can be drawn. (1) Gallotia galloti has the features of an ideal bioindicator: high sensitivity to OPs and extremely slow recovery of serum BChE with respect to other vertebrate species; this property extends the temporal application of this biomarker in field studies. (2) A high correlation was found between the destructive biomarker brain AChE and the nondestructive biomarker serum BChE, 24 h after treatment. (3) The results of the field study show the relative 'non-toxicity' of Trichlorphon for nontarget organisms, such as lizards, at the average concentrations used in agriculture.

Treatment of wastewater effluents with Phillipsite-rich tuffs.

The presence of abundant zeolites in association with volcanic pumiceous materials in Tererife (Canary Islands) prompted us to study their properties as a water purifying bed for inorganic contaminants, pathogenic bacteria, and soluble organic matter. The experimental model used was a chemical percolation reactor with a constant flux of solution, where the fixation kinetics were studied by comparing the input and the output solutions. The ammonium and phosphate retention values found after 10 days of constant percolation were 70% and 14%, respectively. In addition, a high reduction of soluble organic matter was observed, as well as the total removal of the bacteria species studied. The N-P-K values of the soluble and exchangeable nutrients indicate the potential capacity of the bed as a slow-release fertilizer.