Andrej Jaklin

• Ph.D.
• Professor (Assistant) at Rudjer Boskovic Institute

The shells of dead Pinna nobilis individuals are important habitats in sedimentary coastal ecosystems, yet their ecological role is poorly understood. This study investigated macrofaunal communities associated with 80 P. nobilis shells from Soline Bay and Valovine Bay, northern Adriatic, analyzing variations in species abundance and biodiversity be...

The condition index is an important indicator of the physiological and health status, as well as the quality, of mussels. Standardised sampling and a suitable methodology for analysing the condition index of the Mediterranean mussel (Mytilus galloprovincialis) are the most important basis for longterm quality monitoring, enabling quality assessment...

Recently, large numbers of Polyclad flatworms (Stylochus mediterraneus) have been observed in Istrian County shellfish farms connected to intensive ascidian fouling. To assess a possible threat and determine whether the flatworm feeds only on weakened dead mussels or can also infest healthy mussels, we have conducted a field research and laboratory...

Available research on invertebrates in Corallina officinalis settlements shows a high level of biodiversity due to a complex habitat structure. Our aim was to examine seasonal changes in the invertebrate population, considering the algae’s growth patterns. Nine locations with over 90% algal coverage were selected in southern Istria, where quantitat...

A very common intertidal alga, Corallina officinalis, serves as a refuge for numerous invertebrates within its settlements. The composition and structure of invertebrates may differ in relation to different natural or human-induced stress, and this study examined the effects of anthropogenic impact on the abundance and diversity of mollusks residin...

The present study was aimed at identifying geospatial patterns of pollutants including concentrations and toxicity as complex environmental mixtures, in topsoil samples close to petrochemical facilities in the heavily industrialized area of Augusta and Priolo in south-eastern Sicily (Italy). Elemental analysis of soil was conducted by ICP-MS for 23...

The intensive colonial tunicate Clavelina oblonga invasion was observed in the summer of 2020 at shellfish farms located on the western and eastern coasts of the Istrian peninsula (NE, Adriatic, Croatia). Aquaculture facilities create an ideal environment for ascidians, therefore, as a possible environmentally friendly eradication measure, laborato...

Presence of mollusk assemblages was studied within red coralligenous algae Corallina officinalis L. along the southern Istrian coast. C. officinalis turfs can be considered a biodiversity reservoir, as they shelter numerous invertebrate species. The aim of this study was to identify mollusk species within these settlements using DNA barcoding as a...

The knowledge on the hard bottom polychaete assemblages in the Northern Adriatic Sea, a Mediterranean region strongly affected by environmental pressures, is scarce and outdated. The objective of this paper was to update the information on polychaete diversity and depict their patterns of natural spatial variation, in relation to changes in algal c...

Red coralligenous algae Corallina officinalis provides shelter to many invertebrate species from wave actions, predation and desiccation stress in the intertidal area. Physical structure and complexity of the habitat have a major influence on biodiversity of this community. The aim of this preliminary study was to examine the diversity of invertebr...

Characterization of soft-bottom communities in surveyed ports of Bari, Ancona Koper, Pula, Rijeka

The present paper is a contribution to the first initiative of the Port Baseline Survey (PBS) for Non-indigenous species (NIS) in the Mediterranean Sea. It presents a report on the soft-bottom macrobenthos from the five Adriatic ports: Bari, Ancona (Italy), Koper (Slovenia), Pula, Rijeka (Croatia), with a focus on the presence and contribution of N...

The sea hare Bursatella leachii (de Blainville 1817) (Mollusca: Gastropoda: Heterobranchia: Aplysiidae) is a pantropi‑cal sea slug that has colonized the Mediterranean Sea in modern times. Because the initial records in the non‑native range started in the Eastern Mediterranean, and its pattern of spread was relatively consistent with those observed...

Port baseline surveys (PBS) provide species inventories in and around ports, with a focus on non-indigenous species that may have been introduced by vessels, primarily via ballast water. PBS are an essential tool to support effective management strategies for non-indigenous as well as native harmful aquatic organisms and pathogens (HAOP). This pape...

The intense shipping traffic characterising the Adriatic Sea favours the spread of marine organisms. Yet, a study of 12 Adriatic ports (4 on the western side and 8 on the eastern side of the basin) found that non-indigenous species (NIS) accounted for only 4% of the benthic communities settled on hard substrates. The cirripeds Amphibalanus amphitri...

We herein review the Adriatic opisthobranch fauna, provide an updated checklist of 223 species and assess their distribution at regional and country levels. New Adriatic records are provided for 67 opisthobranch taxa, adding three new records for the Italian coastline, five new records for Albania, eight for Croatia and 15 for Montenegro. The prese...

The difficulty in teasing apart the effects of biological invasions from those of other anthropogenic perturbations has hampered our understanding of the mechanisms underpinning the global biodiversity crisis. The recent elaboration of global-scale maps of cumulative human impacts provides a unique opportunity to assess how the impact of invaders v...

ANOVA on the response of canopy-forming macroalgae to experimental treatments. Table S2–ANOVA on the effects of Site (3 levels, random), Assemblage (control versus cleared; fixed) and C. cylindracea (present versus removed; fixed) on the percentage cover of canopy-forming species. Pooling procedures were used, according to Winer et al. (1991).

Dataset of extant assemblages.

Dataset of recovering assemblages.

Table S1–Influence of an outlier on the analysis of species richness in developing assemblages. Linear-mixed models assessing the effects of C. cylindracea, land-based- and sea-based cumulative human impacts on the species richness of developing assemblages after the exclusion of a potential outlier. Coefficients, standard errors (SE) and p-values...

Biological invasions threaten biodiversity worldwide. Nonetheless, a unified theory linking disturbance and resistance to invasion through a mechanistic understanding of the changes caused to biodiversity is elusive. Building on different forms of the disturbance-biodiversity relationship and on the Biotic ResistanceHypothesis (BRH), we constructed...

Appendix S1. Description of thallus morphology of the different species of Cystoseira.

Appendix S3. ANOVA assessing the effects of disturbance, canopy species richness and composition on Caulerpa.

Appendix S4. Relationships between Caulerpa and Cystoseira spp. cover in fall 2010.

Appendix S2. ANOVAs comparing the cover of the different canopy‐forming macroalgae and species richness among treatments.

Artificial structures are sprawling in marine seascapes as a result of burgeoning coastal populations, increasing development and energy demand, and greater risks from climate change, storm surges and sea level rise. Interest in designing marine developments that maintain vital ecosystems and critical services is growing, but progress requires unde...

Development of the national coralligenous monitoring protocol has been recently initiated in Croatia in the framework of the MedMPAnet project, with intention to primarily fulfill reporting and monitoring requirements of the EU Habitat Directive (92/43/EEC). However, basic information on coralligenous habitat along the Croatian coast is still lacki...

X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM), environmental scanning electron microscopy (ESEM) and energy dispersive X-ray analysis (EDS) were used in study of starting biomineralization processes in embryos of the sea hare speci...

Spatial priorities for the conservation of three key Mediterranean habitats, i.e. seagrass Posidonia oceanica meadows, coralligenous formations, and marine caves, were determined through a systematic planning approach. Available information on the distribution of these habitats across the entire Mediterranean Sea was compiled to produce basin-scale...

Sponges (Porifera), in general, are pumping water through their bodies. This water contains planktonic eukaryotic and procaryotic organisms as well as particulate and dissolved organic matter as potential food source. We analyzed the eukaryotic unicellular plankton fraction from water surrounding sponges of the species Aplysina aerophoba, Nardo 188...

The aim of this study is to test the effects of fine scale (microhabitat) environmental variation on the distribution of bryozoan species and potential variation in growth habit diversity and disparity. Data are derived from six microhabitats in replicate, on designed apparatuses, providing surfaces of varied complexity and orientation. The apparat...

Molluscs are a diverse and ubiquitous group of organisms which contribute to the formation of biogenic sediments and are one of the major prey taxa for the neritic-stage loggerhead sea turtles (Caretta caretta) worldwide. Here we investigated to what degree molluscs contribute to the diet of individual turtles, and what role the feeding strategy of...

In the Mediterranean Sea, two species of the genus Aplysina Nardo, 1834 (Demospongiae, Verongida, Aplysinidae) co-occur, both described by Schmidt in 1862. The first one was named Aplysina aerophoba (formerly Verongia aerophoba) due to the change of its bright yellow pigment uranidine to dark blue when exposed to air. The second one was named Aplys...

Marine sponges are becoming important objects of multiple research purposes. Identification, sampling and culturing, however, are facing a multitude of problems needing an acute scientific attention. Experience in the in situ and ex situ culturing of sponges, the sampling of sponges following safety standards during diving as well as scientific pur...

The sponge Aplysina aerophoba Schmidt, 1862 (Demospongiae, Verongida, Aplysinidae) is one of the most common sponges in the Limski kanal. The family Aplysinidae Carter, 1875 is a potential source for natural bioactive products. The information about sponge distribution patterns and their dependence on light, depth, substrate and other factors could...

Free-lying colonies of bryozoans that grew as thin sheets over fine-grained marine sediments were common during the Paleozoic but apparently have been uncommon for the past 245 million years. Decline in this free-lying growth habit corresponded in general with rise in intensity of marine bioturbation, which has been implied to be a cause of the dec...

Background and Purpose: Through centuries sponges and other marine invertebrates have been widely affected by their use in commercial trade and for human benefit, including usage for public aquaria and in scientific research. Sponge populations are also affected by bottom fishing and by pollution. Due to the limited knowledge about the extent of th...

Autecology of most sponge species, including Suberites domuncula in the Adriatic Sea, is still unknown, as there are gaps in our knowledge of, for example, growth, migration, behavior, and symbiosis. The main objective of this study was to compile additional contributions on the contraction phenomena of S. domuncula. Specimens of S. domuncula were...

The green alga Caulerpa taxifolia was recorded at Malinska in 1994 and this actually represents the highest northern latitude (45°7′30″N) at which this invasive alga has been found in the world. The alga was widespread at four sites from which it was eradicated by suction pumps during 1996 and 1997. However, it immediately and intensively recoloniz...

The coastal seabed around the northern Adriatic islands of Prvić, Sv. Grgur, Goli have remained little researched until recently, Therefore, we compiled here results of our studies on macroflora, fauna, and bottom communities. The benthos was surveyed by scuba diving at 26 sites and a fish census taken at 14 of them. Bottom trammel nets were used a...

A marine meadow covered 80–90% by a turf of the erect bryozoan Cellaria occurs over an area >104 m2 west of Banjole Island (Croatia) in the northeastern Adriatic Sea. Surrounding areas are bare to patchily covered by isolated clumps of bryozoans, sponges, and ascidians attached to scattered shell and rock debris.Silt and clay comprise >90% of the m...

The tropical green alga Caulerpa taxifolia in the Mediterranean has spread steadily since its introduction in 1984. At the end of 2000, approximately 131km2 of benthos had been colonized in 103 independent areas along 191km of coastline in six countries (Spain, France, Monaco, Italy, Croatia and Tunisia). Large regions neighboring the invaded areas...

Background and purpose: The Adriatic Sea region is mainly built of mesozoic limestones. Exceptions of magmatic origin are the two islets Jabuka and Brusnik, and a small part of the Vis Island. Jabuka remained poorly explored due to its lonesome offshore position and inaccessibility of its shore. Benthic communities zonation and spatial distribution...

The project "Biodiversity in the Preservation in the Adriaic Sea" is created to promote a special protection of selected areas. The network of specially protected areas (marine parks, fish reserves, special reserves etc.) in the Croatian part of the Adriatic Sea with strictly defined management regulation has an aim to preserve and to protect the b...

A diverse assemblage of foraminiferans, rhodophytes, sponges, hydroids, bryozoans, polychaete annelids, and ascidians lives within the dense mat formed by branches of the erect bryozoan Cellaria salicornioides that carpets a 35 m deep 'meadow' west of Banjole Island offshore of Rovinj, Croatia. A variety of modular growth habits predominates among...

Fourteen years after the first observation of Caulerpa taxifolia (Valh) C. Agardh in the northwestern Mediterranean Sea, this green alga of tropical origin is now present in five countries (Spain, France, Monaco, Italy and Croatia). By the end of 1997, more than 46 km(2), at depths of between 0 and 50 m, were found to be affected by this expansion....

Background and purpose: The project PRESERVATION OF BIODIVERSITY IN THE ADRIATIC SEA is designed to promote a special protection of selected areas - marine parks - along the Croatian coast of the Adriatic Sea, primarily with an aim to preserve and protect the biodiversity and enable undisturbed natural reproduction of the economically important mar...

2,6-Dimethylheptyl sulfate (1) was isolated for the first time from a marine ascidian from Policitor adriaticus Drasche (class Ascidiacea, order Aplousobranchiata, family Polycitoridae). In this work, the absolute stereochemistry at C-2 of 1 was determined by 1H-NMR analysis of its (+)- and (−)-methoxy(trifluoromethyl)phenylacetic acid (MTPA) ester...

An account is given of the elysiid sacoglossans collected on diving expeditions to the eastern Mediterranean shores of Yugoslavia and Greece during the period 1978–1986, supplemented by material collected around Naples and some preserved specimens from other Mediterranean localities. In all, 6 species of Elysia and 1 of Bosellia were investigated,...