http://faculty.jsd.claremont.edu/emorhardt/159/pdfs/2007/3_29_07.pdf

Global change and marine communities: Alien species and climate change

The Black Sea ecosystem suffered catastrophically during the 1980s and early 1990s from the effects of eutrophication and the arrival of an invasive species, the ctenophore
 Mnemiopsis. However, this ecosystem is now on the road to recovery due to a decline in nutrient input from rivers such as the Danube that feed into the Black Sea, and the arrival of another ctenophore
 Beroe, a natural predator of
 Mnemiopsis.

https://science.sciencemag.org/content/sci/297/5586/1482.full.pdf

Fall and Rise of the Black Sea Ecosystem

European brackish water seas (Baltic Sea, Black Sea and Sea of Azov, Caspian Sea) are subject to intense invasion of non-indigenous species (NIS). In these seas, salinity is the most important range limiting factor and native species seem to reach a minimum species richness at intermediate salinities. This trend, revealed by Remane in 1934 and later on confirmed by many other scientists, was compared to the salinity range of already established NIS in the European brackish water seas. It turned out that most NIS are well adapted to the salinities holding lowest native species richness, already in their native area, and that NIS richness maximum in brackish water seas occurs in the salinity intervals of native species richness minimum. A predictable pattern in the salinity range of NIS can be used as a tool in initial risk assessment of future invasions in brackish water seas, especially when mapping highly potential donor and recipient areas. A product of empty niches, suitable environmental conditions, and availability of proper vectors might be the most effective predictor for the invasibility of brackish water areas.

Are invasive species most successful in habitats of low native species richness across European brackish water seas

Assessment of biopollution in aquatic ecosystems

A large population of a previously unreported jellyfish occurred across the northern Gulf of Mexico (USA) from May through September of 2000. The jellyfish, identified as Phyllorhiza punctata by von Lendenfeld (1884), is not indigenous to the Gulf of Mexico or to the Atlantic Basin. Current theory states that this invasive species was introduced into the Atlantic from the Pacific Ocean through the Panama Canal about 45 years ago, and several confirmed reports indicated that a cryptic population may have existed in the northern Gulf since 1993. However, mesoscale hydrographic anomalies in spring 2000 may have directly transported the population from the Caribbean Sea where populations of P. punctata have been reported previously in Puerto Rico. We undertook a rapid-response sampling program from June through September to obtain ecological information regarding P. punctata in the highly productive northern Gulf waters. Jellyfish bell diameter increased by about 50% (from an average of 32 ±12 to 45 ± 6 cm) as animals invaded nearshore waters during July. As the summer progressed, a net westerly distribution shift followed nearshore currents to an accumulation point near the mouth of Lake Borgne, Louisiana, in the far western Mississippi Sound. In the Lake Borgne aggregation, we estimated 5.37 × 106 medusae over an area of about 150 km2. All of the medusae appeared to lack the symbiotic algae that are present in all other described populations, and therefore must have depended solely on planktivory for their nutrition. Clearance rates estimated from ambient zooplankton, gut contents and published digestion times ranged from <1 m3 d−1 for adult copepods to over 90 m3 d−1 for fish eggs. Based on these clearance rates, the central core of this aggregation (30 km2) was being turned over at least once per day with even higher turn-over in very concentrated’ super-swarms’. Clogging of shrimp nets was the greatest economic impact,and perhaps contributed to millions of dollars in economic losses. The indirect effect of predation on eggs and larvae of commercially important finfish and shellfish remained intangible in the determination of economic effects. In 2001, P. punctata has recurred along southern Louisiana and has apparently spread into the coastal and lagoonal waters of the Florida east coast.

Ecological and economic implications of a tropical jellyfish invader in the Gulf of Mexico

Vladimir P. Ivanov1, Andrey M. Kamakin1, Vladimir B. Ushivtzev1, Tamara Shiganova5, Olga Zhukova1, Nikolay Aladin2, Susan I. Wilson3, G. Richard Harbison4 & Henri J. Dumont6,∗ 1CaspNIRH, Astrakhan, Russia; 2Brackish Water Laboratory, Russian Academy of Sciences, St.-Petersburg, Russia; 3School of Biology and Biochemistry, Queens University, Belfast, UK; 4Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA; 5P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia; 6Laboratory of Animal Ecology, Ghent University, Belgium; ∗Author for correspondence (e-mail: Henri.Dumont@rug.ac.be)

/pdf/invasion-of-the-caspian-sea-by-the-comb-jellyfish-mnemiopsis-2nd72ca9e6.pdf

Nikolay Aladin

Papers

Invasion of the caspian sea by the comb jellyfish mnemiopsis leidyi (ctenophora)