Daria Ezgeta Balic

Institute of Oceanography and Fisheries | IZOR · Laboratory of Fisheries Science and Management of Pelagic and Demersal Resources

To understand the response of marine species to a changing environment, it is crucial to have deep insight into their main biological traits. This study used a multi-species approach to comparatively analyse the reproductive and growth strategies of three commercially important scallop species. Target taxa were larger sized Mediterranean scallop Pe...

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....

We examined how the trophic ecology of nine economically important marine taxa varied across three distinct areas of the Adriatic Sea. These taxa included three species of demersal fishes (European hake Merluccius merluccius, red mullet Mullus barbatus, black-bellied angler Lophius budegassa) and two species of decapod crustaceans (Norway lobster N...

Beam trawl fishery is highly important in the Croatian part of the northern Adriatic wherein 116 vessels have a licence for this type of fishing gear. A sharp decrease in the beam trawl catch observed since 2015 has raised concern about not only socio-economic issues but also ecological issues and the effect that beam trawl fisheries have had on ex...

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 penins...

In order to detect the possible regulatory effect of non-native C. gigas on the native O. edulis, under aquaculture conditions, feeding interactions between them were investigated in a highly productive environment of Lim Bay (Adriatic Sea). The present study uses a multi-methodological approach, including stomach content, DNA barcoding and stable...

The Pacific oyster Crassostrea gigas has been 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 coast of the Adriatic Sea. Interestingly , in the 1970s, the Pacific oyster was reported in the natural habitats of Lim Bay, Croa...

The aim of this research was to summarize existing and novel data on the distribution of M. gigas in coastal areas of the Eastern Adriatic and to provide a baseline for the future monitoring and assessment programmes of the species. Distribution of M. gigas was determined by three different methods: (i) a visual census of the presence of M. gigas s...

Searching for Amnesic (ASP), Paralytic (PSP) and Lipophilic (LT) toxins in seafood is of great importance for consumer protection. Studies are usually focused on the most aquacultured species, the mussel. But, there are a number of potentially commercially important shellfish species as rough cockle Acanthocardia tuberculata (Linnaeus, 1758) and sm...

Potentially important species in shellfish aquaculture, cockle Acanthocardia tuberculata and sweet clam Calista chione are widespread in the Croatian Adriatic Sea. Assessment of the potential toxin profile of the natural populations of cockle and sweet clam were monitored from March 2009 to February 2010, one per month, with the purpose of a prelim...

Seasonal changes of food sources were investigated by analysing the fatty acid profiles of digestive gland and muscle tissues of the naturally occurring clams Glycymeris nummaria in Mali Ston Bay, Croatia. Total lipids in the digestive gland and the adductor muscle showed parallel changes, with a maximum after the main spawning event in September....

We examined the stomach contents of two of the most economically and ecologically important small pelagic fish species, the sardine, Sardina pilchardus and the anchovy, Engraulis encrasicolus, obtained monthly from commercial purse-seine catches operating on Croatian fishing grounds during a one-year period (January–December, 2011). Both species ge...

Longevity of bivalves has been an intriguing issue, especially for those species of interest for human consumption. Reliable age and growth estimates often require the combination of several methods. In this study, we analyzed changes in shell structure including ridges on the external shell surface and growth lines observed in acetate peel replica...

The age and shell growth patterns in populations of Patella rustica in the Adriatic Sea were determined by analyzing the inner growth lines visible in shell sections. Marginal increment analysis showed annual periodicity with the annual growth line being deposited in May. The growth analysis of 120 individual shells showed that 90.8 % of collected...

The reproductive cycle of the high shore limpet Patella rustica is described based on histological analysis as the primary method of staging gonad development. Sex ratios, shell length at sexually maturity, gonad developmental stages, mean gonad index and oocyte size were investigated. Males and females were found to differ in size distribution, wi...

Glycymeris bimaculata is one of the largest (up to ~ 115 mm) bivalves in the Mediterranean Sea, yet there is a paucity of information about the biology, ecology and growth of the species. Maximum longevity, growth and periodicity of internal shell growth line formation were assessed in individuals collected from Pag Bay in the Adriatic Sea. We vali...

In support of aquaculture development and sustainable fisheries, survival, condition index, and stable isotope composition of the commercially important bivalve species Arca noae were investigated on individuals suspended in the water column at 2 distances from fish cages and those collected from natural populations. Significant differences were re...

The feeding ecology of four bivalve species co-occurring in the Mali Ston Bay, the most important bivalve aquaculture area of the Eastern Adriatic, were investigated by analysing the stable isotope composition and lipid content in two tissue types. Analyses included two cultured species: Mytilus galloprovincialis and Ostrea edulis, and two naturall...

In support of aquaculture development and sustainable fisheries, survival, condition index, and stable isotope composition of the commercially important bivalve species Arca noae were investigated on individuals suspended in the water column at 2 distances from fish cages and those collected from natural populations. Significant differences were re...

The reproductive cycle of the dog cockle, Glycymeris nummaria (Glycymerididae), was studied using specimens collected monthly from Mali Ston Bay, southeastern Adriatic Sea over the period from January to December 2010. We analysed sex ratios, gonad developmental stages, and oocyte diameters using standard histological techniques. There were no diff...

Based on the mechanism of food collection, bivalves can be suspension–feeders or deposit–feeders, or even utilize both feeding methods. Although some au-thors describe bivalve feeding as "automatized" process, recent studies show that some bivalves species have ability to regulate filtration and select particles based on their size, shape, nutritiv...

Bivalves are an abundant group of organisms in majority of costal marine ecosystems and they play an important role in the marine food webs. Understanding of bivalve feeding ecology has great importance especially in aquaculture areas where cultured species usually occur at high densities. This thesis presents data about feeding ecology of four com...

Pinna nobilis is a large bivalve, endemic to the Mediterranean Sea that was shown in a previous study to ingest significantly different proportions of different food items according to its shell height. Fatty acid profiling of total lipids was used to examine these differences in diet in relation to shell size. Small (shell height 23.0 ± 3.3 cm), m...

The warty venus (Venus verrucosa Linnaeus, 1758) is commercially one of the most important bivalves in the Mediterranean Sea. Studies of reproductive cycle and gonad development of this species were conducted in Kaštela Bay, eastern Adriatic Sea, in a period between March 2009 and February 2010. We analysed sex ratios, gonad developmental stages, p...

The growth rates of Venus verrucosa collected from five locations in the eastern Adriatic Sea, were studied using shell-sectioning techniques. At each sampling site, mean shell lengths at ring formation were asseessed and von Bertalanffy growth curves fitted. Asymptotic length (Linf) values ranged between 48.2 mm (Istria) to 57.9 mm (Pag Bay) and t...

Some bivalve molluscs are capable of zooplankton ingestion, however that aspect of their ecology is still relatively poorly studied. The objective of this investigation was to contribute to the understanding of size structure of zooplankters ingested by four commercially important bivalve species co-occurring in the same area. The study was perform...

Growth and longevity of Glycymeris nummaria were determined from samples of shells, collected monthly by scuba divers between January 2010 and December 2010 from Mali Ston Bay, eastern Adriatic Sea. Acetate peel replicas of the shell margin (marginal increment analysis) and hinge region of the shell were used to validate an annual periodicity of gr...

Age, growth and condition index of commercially important chequered carpet shell Venerupis decussata (Linnaeus, 1758) were studied in the Pag Bay - eastern Adriatic Sea. Monthly samples were collected from commercial catch from January to November 2007. Age and growth were determined from internal growth bands of 69 shells ranging in length from 17...

Noah’s ark shell Arca noae Linnaeus, 1758 is one of the most important commercially exploited bivalve species in the eastern Adriatic Sea. High harvesting pressure, as a consequence of increasing market demands, could in the future result in its overexploitation in some areas. All mentioned above, together with a high market price, make A. noae a n...

To assess the potential of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) for aquaculture in southern Croatia, we analyzed their survival and growth rates under two experimental conditions—suspended culture and on-bottom culture. Furthermore, we investigated feeding on zooplankton by these two species in suspended cul...

This study provides information about differ-ences in composition of ingested zooplankton amongst bivalve species coexisting in the same area in a period from May 2009 to December 2010. The study was conducted at the Mali Ston Bay (42°51 0 N, 17°40 0 E)—the most important bivalve aquaculture area in the eastern Adriatic Sea. Stomach content analysi...

Knowledge of bivalve food sources has great importance in aquaculture areas where cultured species usually occur at higher densities than in natural populations. Except phytoplankton, which is considered as their primary food sources, bivalves can use other food sources such as detritus, bacteria and zooplankton. The objective of this study was to...

A study of the age, growth and population structure of Acanthocardia tuberculata from the eastern Adriatic Sea was carried out. The condition index analysis identified one reproductive peak, which occurred between April and May, for a population of A. tuberculata in the Cetina River estuary with uni-modal recruitment. Annual growth rings on the ext...

In the aim to better understand the dynamics of diarrhetic shellfish poisoning (DSP) contamination in Mali Ston Bay, the most important bivalve aquaculture area in the eastern Adriatic Sea, a field study was carried out to detect differences in phytoplankton cells accumulation in two commercially cultured shellfish species; the mussel Mytilus gallo...

The age, growth, and population structure of the smooth clam Callista chione were determined from samples collected by hydraulic dredge and SCUBA at four locations in the eastern Adriatic during 2007 and 2008. The age of 436 clam shells was determined from internal growth lines present in shell sections, and the timing of growth line formation was...

The endangered fan shell Pinna nobilis is a large bivalve mollusc (<120 cm shell length) endemic to the Mediterranean that lives one-third buried in soft substrata, generally in shallow coastal waters. We hypothesised that P. nobilis of different sizes would ingest different food sources, because small fan shells will inhale material from closer to...

Clearance rates, respiration rates and food absorption efficiencies of the commercially interesting subtidal bivalve Modiolus barbatus were measured at different temperatures under laboratory conditions and scope for growth calculated. Clearance rates were highest at temperatures from 20 °C to 28 °C, whereas respiration rate was maximal at 9 °C and...

Hydraulic dredge surveys of bivalve communities in the Croatian part of the Adriatic Sea were conducted from the Island of Rab in the north to the river Neretva estuary in the south during 2007 and 2008. The main objective of the study was to describe distribution and community structure of bivalves on soft sediments along the eastern Adriatic, pri...

Hydraulic dredge surveys of bivalve communities in the Croatian part of the Adriatic Sea were conducted from the Island of Rab in the north to the river Neretva estuary in the south during 2007 and 2008. The main objective of the study was to describe distribution and community structure of bivalves on soft sediments along the eastern Adriatic, pri...

Noah's Ark shell Arca noae is an edible bivalve that is commercially exploited in the eastern Adriatic and is harvested primarily by SCUBA divers. There are no reliable data catch statistics data for this species nor there any data on dis-tribution and population biology of exploited stocks, all of which are crucial for establishing sustainable lev...

Noah’s Ark shell Arca noae is an edible bivalve that is commercially exploited in the eastern Adriatic and is harvested primarily by SCUBA divers. There are no reliable data catch statistics data for this species nor there any data on distribution and population biology of exploited stocks, all of which are crucial for establishing sustainable leve...

Based on previous studies, in the East Adriatic Sea (Croatia) the Neretva River estuary has been identified as area of high scientific and commercial interest. This area is particularly suitable for natural shellfish bed especially for clams (Chamelea gallina). A study has been carried out for the evaluation of C. gallina resource with the particip...