| Sažetak | Invazivne vrste su vrste koje prirodno ne žive na nekom području, već su u njega dospjele namjernim ili slučajnim unošenjem, a svojim naseljavanjem i širenjem negativno utječu prvenstveno na bioraznolikost. U Jadranu živi nekoliko vrsta invazivnih mekušaca, a u radu su detaljnije obrađene dvije vrste puževa, Rapana venosa i Crepidula fornicata, te dvije vrste školjkaša, Crassostrea gigas i Mya arenaria. Rapana venosa veliki je azijski puž, iznimno je prilagodljiv i ima visok ekološki fitnes. U sjevernom Jadranu je pronađen 1973.godine. Zbog svoje grabežljivosti smatra se jednom od najnepoželjnih invazivnih vrsta širom svijeta, a može utjecati na prirodne i kultivirane populacije kamenica, dagnji i drugih mekušaca. Crepidula fornicata sjevernoamerička je vrsta rasprostranjena u sjevernom Jadranu. U Europu je unesena 1970-ih, a u Jadranu se pojavljuje nešto kasnije. Štetnik je na kamenicama i dagnjama. Vrsta Crassostrea gigas azijska je vrsta školjkaša vrlo otporna na okolišni stres. Zabilježena je u cijelom Jadranu, a jednom uspostavljena populacija dovodi do promjene staništa, uzrokuje eutrofikaciju, a također i probleme kod uzgoja školjkaša. Zbog velikog utjecaja na okoliš, ova je vrsta proglašena jednom od 100 najinvazivnijih stranih vrsta u Europi. Mya arenaria široko je rasprostranjena vrsta zbog svoje prilagodljivosti različitim okruženjima. Podrijetlom je iz Sjeverne Amerike. Najstarija je dokumentirana vrsta koja je introducirana u europske vode, a u Sredozemlju se pojavljuje 1976. godine. U kompeticiji je s drugim vrstama, uzrokuje abiotičke promjene i koristi resurse. Zbog svoje veličine, brojnosti, dugovječnosti i jednostavnosti prepoznavanja koristi se kao indikatorska vrsta i vrsta pogodna za monitoring. Vrste C. gigas i M. arenaria unesene su i šire se balastnim vodama i preko obraštaja brodova, a osim ovim putem, vrste R. venosa i C. fornicata unose se i šire različitim vektorima te slučajnim prijenosima u akvakulturi (mlađi kamenica). Otkriveno je da C. gigas ima pozitivan efekt na druge invazivne vrste poput puževa C. fornicata i R. venosa. |
| Sažetak (engleski) | Invasive species are species that do not naturally live in some area but they have entered with the intentional or accidental introduction, and their settlement and expansion have a negative impact primarily on biodiversity. In the Adriatic, there are a few species of invasive molluscs, and in this work two species of snails are introduced, Rapana venosa and Crepidula fornicata, and two species of shellfish, Crassostrea gigas and Mya arenaria. Rapana venosa is a big Asian snail, extremely flexible and has a high ecological fitness. It was found in the northern Adriatic in 1973. Because of its greed it is considered as one of the most undesirable invasive species worldwide and can affect the natural and cultivated populations of oysters, mussels and other molluscs. Crepidula fornicata is a North American species that is widely spread in the northern Adriatic. In Europe it was introduced in the 1970s, and in the Adriatic it appeared a few years later. The pest is on the oysters and mussels. Crassostrea gigas is an Asian species of shellfish which is highly resistant to environmental stress. It is recorded in the Adriatic Sea, and once established population leads to changes in habitat, causing eutrophication, as well as problems in shellfish farming. Due to the large environmental impact, this species was declared as one of the 100 most invasive alien species in Europe. Mya arenaria is a widely spread species because of its adaptability to different environments. It originates from North America. It is the oldest documented species that has been introduced into European waters and it appeared in the Mediterranean in 1976. It is compeeting with other species, causing abiotic changes and using resources. Due to its size, population size, long life and ease of recognition is used as the indicator species and species suitable for monitoring. C. gigas and M. arenaria were introduced and spread via ballast water and fouling of ships, and in addition, species R. venosa and C. fornicata enter and spread with variety of vectors and random transfers in aquaculture (spat of oysters). Scientists found out that C. gigas had a positive effect on other invasive species like snails C. fornicata and R. venosa. |
