Das Potential von Tauchklubs bei der Verringerung von Abfall im Meer, der jetzige Zustand und die Perspektive in Kroatien

Morski otpad je veliki globalni ekološki problem današnjice uglavnom kao posljedica sve veće upotrebe plastike i neodgovarajućeg gospodarenja otpadom na kopnu. Prilikom dospijevanja u more većina otpada potone na dno u priobalnim područjima gdje se može godinama nakupljati. Otpad s morskog dna u plitkom priobalju može se jednostavno uklanjati organiziranjem ronilačkih ekoloških akcija. Ronilački klubovi imaju veliki potencijal u takvim akcijama čime se mogu ukloniti značajne količine otpada, međutim one se provode bez usklađene metodologije i koordinacije. Na taj način ostaju nam nepoznati podaci o područjima, količinama i sastavu prikupljenog otpada, koji inače imaju važnost za razvoj strategija za smanjivanje morskog otpada. Razvoj učinkovitih mjera za smanjivanje morskog otpada nužan za očuvanje biološke i gospodarske kvalitete morskog i priobalnog okoliša. U ovom je radu predstavljen potencijal ronilačkih akcija čišćenja plitkog podmorja u smanjivanju količina morskog otpada u Hrvatskoj. Posebno je istaknuta potreba za suradnjom ronilačkih klubova i znanstvenih institucija u cilju dobivanja što kvalitetnijih podataka o prikupljenom morskom otpadu, te važnosti provođenja usklađenog načina prikupljanja podataka čime se može značajno doprinijeti razvijanju spoznaja o sadašnjoj situaciji i trendovima te donošenju odgovarajućih preporuka i zakonodavnih mjera zaštite. Ukoliko se ova inicijativa bude sustavno organizirala i provodila mogla bi djelovati kao značajan program i mjera za smanjivanje količina morskog otpada.Marine waste is a huge environmental problem in the world today, mostly as a consequence of a growing use of plastics and inadequate waste management on the land. When it reaches the sea, most waste sinks to the bottom of coastal areas where it may accumulate for years. Waste from the sea bottom in shallow coastal waters can be easily removed by organising diving environmental activities. Diving clubs have a great potential in such activities to remove significant waste quantities. However, these activities cannot be carried out without a harmonised methodology and coordination, in which case we remain without data on the areas, quantities and compostion of the collected waste that play a significant role in the development of marine waste reduction strategies. A development of efficient measures for marine waste reduction is necessary for preserving biological and economic quality of marine and coastal environments. The paper presents a potential of diving activities in the cleanup of shallow coastal waters and reduction of marine waste quantities in Croatia. A need for cooperation between diving clubs and scientific institutions is particularly emphasized as a manner to obtain high quality data on the collected marine waste, and the importance of a harmonised manner of data collection that could significantly contribute to new insights into the current situation and trends, including adoption of adequate recommendations and legal protection measures. If this initiative is systemically organised and implemented, it could act as an importan programme and a meaasure for reducing the quantity of marine waste.Abfall im Meer ist ein großes globales ökologisches Problem der Gegenwart, der größtenteils als Auswirkung der immer größeren Nutzung von Kunststoffen und einer unangemessenen Müllentsorgung auf dem Land entstanden ist. Beim Gelangen des Abfalls ins Meer sinkt es auf den Grund an der Küste, wo es sich jahrelang ansammelt. Der Abfall vom Meeresgrund kann an seichten Küsten mithilfe von organisierten ökologischen Tauchaktionen einfach entfernt werden. Tauchklubs haben ein großes Potential bei solchen Aktionen, bei denen bedeutende Mengen von Abfall entfernt werden können, doch sie werden ohne abgestimmte Methodologie und Koordination durchgeführt. So bleiben uns Informationen/Daten über Gebiete, Mengen und Zusammensetzungen des gesammelten Abfalls unbekannt, die eigentlich wichtig zur Entwicklung von Strategien zur Verminderung von Abfall im Meer sind. Die Entwicklung wirksamer Methoden zur Verminderung von Abfall im Meer ist notwendig für den Schutz der biologischen und wirtschaftlichen Qualität der Umwelt im Meer und an der Küste. In dieser Arbeit ist das Potential von Tauchaktionen zur Säuberung der seichten Unterwassergebiete bei der Minderung der Quantität von Abfall im Meer in Kroatien vorgestellt. Besonders hervorgehoben ist die Notwendigkeit der Zusammenarbeit zwischen Tauchklubs und wissenschaftlichen Institutionen, mit dem Ziel umso hochwertiger Daten über den gesammelten Abfall zu erhalten sowie die Wichtigkeit einer angepassten Art der Datensammlung. Dabei können bedeutende Erkentnisse über die heutige Situation und Trends erhalten werden sowie die entsprechenden Empfehlungen und rechtlichen Schutzmittel erlassen werden. Falls diese Initiative systematisch organisiert und durchgeführt wird, könnte sie als bedeutsames Programm und Mitter zur Verminderung von Abfall am Meeresgrund wirken

Das Potential von Tauchklubs bei der Verringerung von Abfall im Meer, der jetzige Zustand und die Perspektive in Kroatien

Morski otpad je veliki globalni ekološki problem današnjice uglavnom kao posljedica sve veće upotrebe plastike i neodgovarajućeg gospodarenja otpadom na kopnu. Prilikom dospijevanja u more većina otpada potone na dno u priobalnim područjima gdje se može godinama nakupljati. Otpad s morskog dna u plitkom priobalju može se jednostavno uklanjati organiziranjem ronilačkih ekoloških akcija. Ronilački klubovi imaju veliki potencijal u takvim akcijama čime se mogu ukloniti značajne količine otpada, međutim one se provode bez usklađene metodologije i koordinacije. Na taj način ostaju nam nepoznati podaci o područjima, količinama i sastavu prikupljenog otpada, koji inače imaju važnost za razvoj strategija za smanjivanje morskog otpada. Razvoj učinkovitih mjera za smanjivanje morskog otpada nužan za očuvanje biološke i gospodarske kvalitete morskog i priobalnog okoliša. U ovom je radu predstavljen potencijal ronilačkih akcija čišćenja plitkog podmorja u smanjivanju količina morskog otpada u Hrvatskoj. Posebno je istaknuta potreba za suradnjom ronilačkih klubova i znanstvenih institucija u cilju dobivanja što kvalitetnijih podataka o prikupljenom morskom otpadu, te važnosti provođenja usklađenog načina prikupljanja podataka čime se može značajno doprinijeti razvijanju spoznaja o sadašnjoj situaciji i trendovima te donošenju odgovarajućih preporuka i zakonodavnih mjera zaštite. Ukoliko se ova inicijativa bude sustavno organizirala i provodila mogla bi djelovati kao značajan program i mjera za smanjivanje količina morskog otpada.Marine waste is a huge environmental problem in the world today, mostly as a consequence of a growing use of plastics and inadequate waste management on the land. When it reaches the sea, most waste sinks to the bottom of coastal areas where it may accumulate for years. Waste from the sea bottom in shallow coastal waters can be easily removed by organising diving environmental activities. Diving clubs have a great potential in such activities to remove significant waste quantities. However, these activities cannot be carried out without a harmonised methodology and coordination, in which case we remain without data on the areas, quantities and compostion of the collected waste that play a significant role in the development of marine waste reduction strategies. A development of efficient measures for marine waste reduction is necessary for preserving biological and economic quality of marine and coastal environments. The paper presents a potential of diving activities in the cleanup of shallow coastal waters and reduction of marine waste quantities in Croatia. A need for cooperation between diving clubs and scientific institutions is particularly emphasized as a manner to obtain high quality data on the collected marine waste, and the importance of a harmonised manner of data collection that could significantly contribute to new insights into the current situation and trends, including adoption of adequate recommendations and legal protection measures. If this initiative is systemically organised and implemented, it could act as an importan programme and a meaasure for reducing the quantity of marine waste.Abfall im Meer ist ein großes globales ökologisches Problem der Gegenwart, der größtenteils als Auswirkung der immer größeren Nutzung von Kunststoffen und einer unangemessenen Müllentsorgung auf dem Land entstanden ist. Beim Gelangen des Abfalls ins Meer sinkt es auf den Grund an der Küste, wo es sich jahrelang ansammelt. Der Abfall vom Meeresgrund kann an seichten Küsten mithilfe von organisierten ökologischen Tauchaktionen einfach entfernt werden. Tauchklubs haben ein großes Potential bei solchen Aktionen, bei denen bedeutende Mengen von Abfall entfernt werden können, doch sie werden ohne abgestimmte Methodologie und Koordination durchgeführt. So bleiben uns Informationen/Daten über Gebiete, Mengen und Zusammensetzungen des gesammelten Abfalls unbekannt, die eigentlich wichtig zur Entwicklung von Strategien zur Verminderung von Abfall im Meer sind. Die Entwicklung wirksamer Methoden zur Verminderung von Abfall im Meer ist notwendig für den Schutz der biologischen und wirtschaftlichen Qualität der Umwelt im Meer und an der Küste. In dieser Arbeit ist das Potential von Tauchaktionen zur Säuberung der seichten Unterwassergebiete bei der Minderung der Quantität von Abfall im Meer in Kroatien vorgestellt. Besonders hervorgehoben ist die Notwendigkeit der Zusammenarbeit zwischen Tauchklubs und wissenschaftlichen Institutionen, mit dem Ziel umso hochwertiger Daten über den gesammelten Abfall zu erhalten sowie die Wichtigkeit einer angepassten Art der Datensammlung. Dabei können bedeutende Erkentnisse über die heutige Situation und Trends erhalten werden sowie die entsprechenden Empfehlungen und rechtlichen Schutzmittel erlassen werden. Falls diese Initiative systematisch organisiert und durchgeführt wird, könnte sie als bedeutsames Programm und Mitter zur Verminderung von Abfall am Meeresgrund wirken

Kljunasta končarica Nemichthys scolopaceus Richardson, 1848 (Pisces: Nemichthydae), novi pripadnik ihtiofaune Jadranskog mora

The paper reports the first record of Nemichthys scolopaceus leptocephalus in the Adriatic Sea, including a detailed description of the specimen with morphometric measurements and meristic counts. A single leptocephalus specimen was caught on 18th September 2016 in south Adriatic with a small mid-water trawl at a depth of approx. 120 meters. Further research is needed to reveal more information about the distribution and potential spawning and nursery areas of slender snipe eel as well as the mechanism of retention and dispersion of their larvae in the Adriatic.U radu je prikazan prvi nalaz vrste kljunasta končarica Nemichthys scolopaceus, ulovljen 18. rujna 2016. godine u južnom Jadranu pelagičkom kočom na dubini od cca. 120 metara. Nalaz se odnosi na ličinku leptocefala te uključuje detaljan opis jedinke s morfometrijskim i merističkim oso- binama. Svakako su potrebna daljnja istraživanja kako bi se otkrilo više o rasprostranjenosti i poten- cijalnim područjima mrijesta i hranilištima ove vrste, kao i o mehanizmu raspršivanja i zadržavanja njihovih ličinki u Jadranu

El gallano, Labrus mixtus (Pisces: Labridae): índices biológicos para documentar la historia vital de la especie y contribuir a su conservación

The cuckoo wrasse, Labrus mixtus, is widely distributed in the moderate warm waters of the Atlantic Ocean, including the Mediterranean and Adriatic Seas. Generally, labrids are small inshore coastal species susceptible to anthropogenic habitat degradation and, although without commercial importance, they make up a significant part of the by-catch and discard. Also, these fishes are intensively caught in recreational and subsistence fisheries. Basic biological information is required for their stock assessment and conservation. Studies of the age, growth, reproduction and feeding of L. mixtus have not been undertaken previously in the Adriatic Sea. The observed maximum age of the cuckoo wrasse was 10 years, although most of the sampled fish were 7 years old. The estimated parameters of the von Bertalanffy growth model suggested that the growth of L. mixtus was relatively fast in the first four years of life. L. mixtus is a protogynous hermaphrodite and sex change occurred at 26 cm, while the greatest increase in gonadosomatic index in April confirmed spring as the spawning period. The cuckoo wrasse is an opportunistic predator, feeding primarily on crustaceans, gastropods and fishes. The information provided on biological indices is necessary for life history pathways and future conservation measures of this population in the Adriatic Sea.El gallano, Labrus mixtus, se halla ampliamente distribuido en las zonas templadas del Océano Atlántico, incluyendo el Mediterráneo y el Mar Negro. En general, los lábridos son especies de pequeño tamaño que habitan en aguas costeras, siendo vulnerables a la degradación antrópica del hábitat y, a pesar de ser comercialmente poco importantes, forman una parte importante de los descartes de la pesca profesional. Estos peces también son intensamente capturados por la pesca recreativa o de subsistencia. Se requiere, pues, una información biológica básica para conocer el estado de los stocks y asegurar su conservación. Los estudios sobre la edad, el crecimiento, la reproducción y la alimentación de L. mixtus no se han realizado hasta ahora en el Adriático. La edad máxima observada en esta especie ha sido de 10 años, si bien la mayoría de los peces capturados se situaba en los 7 años. Los parámetros estimados a partir de la ecuación de crecimiento de Von Bertalanffy sugieren que el crecimiento de L. mixtus es rápido durante los primeros años de vida. L. mixtus es una especie hermafrodita proterogínica y el cambio de sexo se produce a los 26 cm de longitud, mientras que el gran incremento del índice gonadosomático en el mes de abril confirma que el periodo de reproducción se produce durante la primavera. El gallano es un depredador oportunista que se alimenta preferentemente de crustáceos, gasterópodos y peces. La información que se da en este artículo sobre los índices biológicos es necesaria para conocer las características vitales de esta especie y para adoptar futuras medidas de conservación de su población en el Adriático

Characterization of Microplastics in Prapratno Beach Sediment

Mikroplastika predstavlja ozbiljan problem u morskom i priobalnom okolišu. Analiziran je uzorak mikroplastike iz sedimenta plaže Prapratno na poluotoku Pelješcu, Hrvatska. Uzorkovanje i laboratorijsko odvajanje provedeni su prema DeFishGear protokolu. Svaki ispitak svrstan je u određenu kategoriju te je svakom određena masa, boja, prozirnost, maksimalna dimenzija i površina. Identifikacija je provedena infracrvenom spektroskopijom (FTIR) – HATR tehnikom. Otpad s plaže Prapratno sastoji se uglavnom od polietilena te, u manjem udjelu, od polistirena i polipropilena. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Microplastics represent a major problem in the marine and coastal environment. In this work, microplastics from the sediment of Prapratno beach on the Pelješac Peninsula (Croatia) were analysed. Sampling and laboratory separation were performed according to the DeFishGear protocol (Derelict Fishing Gear Management System in the Adriatic Region). The microplastic waste from Prapratno beach sediment consisted of 116 specimens, which could be classified into 6 micro litter categories according to EU TG ML Master List (Fig. 1). Fragments were found to be the predominant category of microplastic waste from the sediment of Prapratno beach, followed by granules, films, pellets and foams, which were present in approximately the same number, while filaments were the least represented category (Fig. 2). The most important categories by mass were granules and fragments, followed by pellets, while films, foams and filaments made up a very small content of the total sample mass (Fig. 3). The numerical contents (Fig. 4), did not correspond to the mass contents (Fig. 3) of individual categories due to the different densities and thicknesses of the specimens in each category. Almost all the base colours were present in the analysed samples (Fig. 5), while 90.52 % of specimens were opaque (Fig. 6). The maximum dimension and surface area of each specimen was determined by Digimizer Image Analysis Software. Maximum dimensions in the range of 1–5 mm were observed in 52.59 % of the specimens, thus belonging to large microplastics (LMP), while 47.41 % of the specimens had maximum dimensions in the range of 5–20 mm, thus belonging to so-called mezzo litter. The distribution of specimen dimensions within LMP is shown in Fig. 8, and within mezzo litter in Fig. 9. The fraction of each category in the total sample surface area is shown in Fig. 10. These results are similar to the numerical fractions of categories, since the samples were generally in the narrow range of maximum dimensions, and thus their numerical fractions corresponded to their fraction in the total surface of the sample. Identification of plastic material was performed by infrared spectroscopy, HATR technique. The obtained spectra were compared with the spectra in the database (Fig. 11–13). The results showed (Fig. 14) that the microplastic waste from Prapratno beach was made of polyethylene (82.46 %), polystyrene (11.40 %) and polypropylene (6.14 %). These polymers came from plastic packaging since polyethylene, polystyrene and polypropylene are the most used polymers for plastic packaging. This work is licensed under a Creative Commons Attribution 4.0 International License

Reproductive cycle of a non-native oyster, Crassostrea gigas, in the Adriatic Sea

The Pacific oyster Crassostrea gigas was introduced for the aquaculture purposes in many different parts of the world. However, the species has never been officially introduced for commercial farming in the Croatian part of the Adriatic Sea. Interestingly, in the 1970s, the Pacific oyster has been reported in the natural habitats of the Lim Bay, in northern Adriatic Sea. Although the species was recorded there, there is a lack of knowledge about its biology and ecology in this region, including a reproductive cycle. Information on the reproductive biology of non-indigenous species in new areas is crucial for prediction of their future survival and possible spread in invaded habitats. In this study, we provide the first data on the reproductive biology of the Pacific oyster in the Adriatic Sea, the northernmost part of the Mediterranean Sea. Quantitative and qualitative methods of gonad tissue analysis were conducted, and effects of environmental conditions on the gametogenesis were evaluated during two reproductive cycles. Our study confirmed that environmental conditions in the Lim Bay were favourable for the reproduction of the species. The Pacific oyster reproduced once per year and had a prolonged spawning period. Water temperature was the main factor affecting gonad development and oocyte size, while chlorophyll a concentration had an impact on the oocyte development in terms of their size.

Plankton diversity in Anthropocene: Shipping vs. aquaculture along the eastern Adriatic coast assessed through DNA metabarcoding

Coastal ecosystems globally are exposed to the most pervasive anthropogenic activities, caused by a suite of human infrastructure and enterprises such as shipping ports, aquaculture facilities, fishing, and tourism. These anthropogenic activities may lead to changes in ecosystem biodiversity, followed by loss of ecosystem functioning and services. Shipping industry and aquaculture have also been recognized as the main vectors for introduction of marine non-indigenous species (NIS) worldwide. In this study, we used DNA metabarcoding-based methods to investigate plankton biodiversity under varying anthropogenic pressures (shipping and bivalve aquaculture) along the eastern Adriatic coast (the northernmost part of the Mediterranean Sea). Our comparative assessment revealed similar community structures among investigated coastal locations (Northern, Central and Southern Adriatic). When the whole plankton communities were considered, they did not differ significantly between port and aquaculture sites. However, the proportion of the unique zOTUs in the port samples was remarkably higher than that in aquaculture sites (40.5% vs 8.2%), indicating that port areas may receive higher abundance and species richness of NIS than aquaculture sites. Further important difference between the two types of anthropogenically impacted habitats was a high abundance of three notorious invaders – M. leidyi, M. gigas, and H. elegans in late summer at the aquaculture site in Northern Adriatic. Therefore, the plankton community of the area is under pressure not only from aquaculture activities, but also establishment of NIS. Port areas are probably under greater introduction pressure from NIS, but aquaculture sites may experience greater community changes due to their establishmen

Plankton biodiversity in Anthropocene: shipping vs. aquaculture along the eastern Adriatic coast

Although anthropogenic activities are widely recognized as a major threat to marine biodiversity, their impacts have not been fully assessed and there is an urge to improve the understanding of the magnitude and mechanisms of those impacts. In this study, we used DNA metabarcoding-based methods to investigate plankton biodiversity patterns under varying anthropogenic pressures (i.e., shipping and bivalve aquaculture) along the eastern Adriatic coast. Our study determined similar community structures among investigated coastal locations in three geographic regions in the Adriatic Sea, as well as between shipping ports and aquaculture sites

Distribution patterns of two co-existing oyster species in the northern Adriatic Sea: The native European flat oyster Ostrea edulis and the non-native Pacific oyster Magallana gigas

The Pacific oyster Magallana gigas, globally one of the most translocated marine species, has never been commercially farmed in any part of the Croatian eastern Adriatic Sea, where the native flat oyster Ostrea edulis is the only cultured oyster species. The Pacific oyster has, however, established populations on the west coast of the Istria peninsula, in the northeast Adriatic Sea. Current distribution, abundance and size structure of the flat and Pacific oysters were studied there along spatial and depth gradients in natural and artificial habitats to assess their potential for coexistence. This is the first quantitative assessment of native and non-native oyster populations on a Mediterranean-wide scale providing a baseline for determining future changes in their distribution. Both species were omnipresent, with the Pacific oyster displaying a more pronounced variability in abundance and size in relation to survey regions and depths. The population density of flat oysters was low, generally less than 1 individual/m(2), with no difference among regions. The density of the Pacific oyster was significantly higher, being on average 5 individuals/m(2). Dense, reef-forming aggregations of Pacific oysters were contained in Lim Bay, a nationally-important shellfish aquaculture area, where its mean density was 107 individuals/m(2). Along the open coastline its densities were considerably lower and followed a latitudinal gradient. The observed abundance and size distribution patterns of the Pacific oyster suggest that Lim Bay was the introduction point, with feral settlement likely originating from short-lived experimental aquaculture trials and subsequently dispersing by prevailing local currents. The flat oysters were larger in size and settled at different depths compared to the Pacific oysters. The vertical range of Pacific oysters was mostly contained in the tidal zone, while flat oysters were present in the subtidal exclusively. Such spatial partitioning likely resulted from introduced oysters occupying a vacant ecological niche and not due to interspecific competitive exclusion. Habitat type had a strong effect on proliferation of Pacific oysters. Artificial hard substrata harboured more abundant and larger Pacific oysters than the natural rocky shore habitat. The possibility of multiple local introduction pathways in ports and marinas is also discussed. Currently, there seems to be no spatial competition between the two oyster species, but as it is hard to predict future possible impacts of non-native species, we strongly suggest regular monitoring of the Pacific oyster, prioritising sensitive and protected areas as well as areas at the edge of its distribution