Use of Sediment Bioassays to Verify Efficacy of Caulerpa taxifolia Eradication Treatments

Infestations of the marine macrophytic alga Caulerpa taxifolia were discovered in Agua Hedionda Lagoon, California in 2000. Rapid response actions included containment under pvc tarps coupled with injection of liquid sodium hypochlorite. To assess the efficacy of these treatments, replicated sediment cores were removed from representative treated sites and transferred to grow-out facilities. Similar cores from uninfested (control) sediments were removed, inoculated with viable explants of C. taxifolia and placed in grow-out facilities. Results from two sampling periods (1 year, 2 years post-treatment) showed that no viable C. taxifolia emerged in cores, and that inoculated “control” sediments supported normal growth. Eelgrass ( Zostera marina L.) seedlings emerged from native seed-banks in “treated” cores, which also supported growth of some invertebrates (annelid worms and hydroids). This study provided essential verification of C. taxifolia eradication efforts, and demonstrates the feasibility of incorporating quality control/quality assurance components in rapid response actions. Results of this study also suggest that seeds of eelgrass are viable for at least two years. (PDF has 9 pages.)

Invasionsoft: a web-enabled tool for invasive species colonization predictions

Predicting and averting the spread of invasive species is a core focus of resource managers in all ecosystems. Patterns of invasion are difficult to forecast, compounded by a lack of user-friendly species distribution model (SDM) tools to help managers focus control efforts. This paper presents a web-based cellular automata hybrid modeling tool developed to study the invasion pattern of lionfish (Pterois volitans/miles) in the western Atlantic and is a natural extension our previous lionfish study. Our goal is to make publically available this hybrid SDM tool and demonstrate both a test case (P. volitans/miles) and a use case (Caulerpa taxifolia). The software derived from the model, titled Invasionsoft, is unique in its ability to examine multiple default or user-defined parameters, their relation to invasion patterns, and is presented in a rich web browser-based GUI with integrated results viewer. The beta version is not species-specific and includes a default parameter set that is tailored to the marine habitat. Invasionsoft is provided as copyright protected freeware at http://www.invasionsoft.com.

Acyclic diterpene alcohols isolated from four algae of Bryopsidophyceae and their toxicity

Three new acylic diterpenoids belonging to the class of phytol series have been isolated. They were obtained from the ethyl acetate soluble fractions of four siphonaceous green seaweeds, Bryopsis pennata Lamour., Caulerpa taxifolia (Vahl) C. Ag., Codium decorticatum (Woodw.) Howe and Valoniopsis pachynema (Mart.) Børg., collected from Karachi coast of Pakistan. Structures of these compounds were elucidated with the help of spectroscopic methods and confirmed by comparison with the known compounds. Even the known compounds are being reported for the first time from a green algal source. All the compounds were found to display a strong toxicity at all the three concentrations tested in the brine shrimp bioassay.

Comparative haemagglutinic activity in the species of Caulerpa and Ulva (Chlorophyta) of Karachi coast

Aquous extracts of 24 species of green seaweeds, 13 of Caulerpa Lamour and 11 of Ulva Linn, were collected from the coastal areas near Karachi, Pakistan and tested for haemagglutination against human erythrocytes of blood groups A,B,AB and O and compared. All the species of Caulerpa and seven of Ulva exhibited a positive activity, the former genus (a member of Bryopsidophyceae) appeared to possess more phycohaemagglutinins than the latter (a member of Ulvophyceae). The haemagglutinic activity proved to be quite helpful in the distinction of various species of both the genera.

The free and combined amino acid contents in species of Caulerpa from southeast coast of India

Caulerpa racemosa var. macrophysa, C. racemosa var cornyphora and C. scalpelliformis are analyzed by quantitative paper chromatographic technique for their amino acid contents in proteins, peptides and free state. It is found that no appreciable variation occurs in the quality of amino acid make up in these algae; but quantitative differences are apparent in them. Moreover, both qualitative and quantitative variations occur in the amino acid make up of the peptides, and in the free state. The results are compared with those of the other investigations.

Taxonomic study of coenocytic green algae commonly growing on the coast of Karachi

Twelve commonly occurring coenocytic and siphonaceous species of marine benthic algae, i.e., Bryopsis pennatta Lamouroux, Caulerpa chemnitzia (Esper) Lamouroux, Ca. faridii Nizamuddin, Ca. manorensis Nizamuddin, Ca. racemosa (Forsskal) J. Agardh, Ca. taxifolia. (Vahl) C. Agardh, Chaetomorpha antennina (Bory de Saint-Vincent) Kutzing, Cladophora uncinella Harvey, Codium decorticatum (Woodward) Howe, Co. flabellatum Nizamuddin, Co. iyengarii Borgesen, and Valoniopsis pachynema (Martens) Borgesen, belonging to four different orders of the class Bryopsidophyceae, division Chlorophyta, were collected from the intertidal region of different coastal areas near Karachi (Pakistan) and investigated taxonomically. Codium decorticatum is a new report from this region and Co. decorticatum, Co. flabellatum and Co. iyengarii are described for the first time from the coast of Pakistan.

Toxic effects of dietary seaweeds Sargassum bovianum, Caulera faridii and Gracilaria corticata on blood parameters of albino rats

The present communication deals with the feeding trials of brown (Sargassum bovianum), green (Caulerpa faridii) and red (Gracilaria corticola) seaweeds in albino rats for a period of thirty days in order to investigate their digestibility and acceptability as supplementary food for animals. The parameters used were: changes in blood hemoglobin, ESR, MCHC, PCV and plasma vitamin levels. The result revealed that all the three species of seaweeds had acceptability up to 5% level, as no ill effect was noted during the experiment. But at 10% and 20% levels, marked changes were observed in blood parameters with diarrhea, vomiting and convulsions indicating possibilities of either tissue and muscular dystrophy, gastrointestinal tract necrosis or functional disorder of central nervous system. A heavy mortality was noted due to excessive water loss through diarrhea and vomiting. However, no mortality was observed after 22nd day at both 10% and 20% levels with subsided clinical signs. The results suggest that these three seaweed species could be used safely as a supplementary food, in native form, in animals at low concentrations.