Puck Bay Research Articles

What has the sea taken from us? Cognitive possibilities of studying artefacts from newly-discovered submerged prehistoric sites in Puck Bay (Gulf of Gdańsk, Baltic Sea)

The article presents the latest results of research in the area of the Bay of Puck. After the last glaciation, the Bay of Puck was gradually flooded by sea water. As a result, we can expect submerged Stone Age sites in this area. The article discusses the latest results of underwater research in this area and analyses in detail four new underwater sites from this region, including a loose find of a bâton percé from Hel dated to about 7000 BC, a collection of flint artefacts, including a flint dagger and pottery from Late Neolithic/Protobronze Age site on Seagull Sandbar and two antler adzes from Site 23 in Puck. A typological and technological analysis of the artefacts was carried out, including analyses of working traces and radiocarbon dating.

Pockmarks and associated fresh submarine groundwater discharge in the seafloor of Puck Bay, southern Baltic Sea

This is the first well-documented report on the occurrence of pockmarks in Puck Bay. Pockmarks in the seafloor of Puck Bay were discovered during a hydroacoustic survey carried out in 2020. They are located at a depth of 25–27 m in the southwestern part of the bay. Significant depletion of chloride (Cl−) concentrations in sediment pore water was found within the depressions. Most likely, the formation of pockmarks was due to groundwater flow through the Miocene–Pleistocene system of aquifers, which extends from land to the bay area. One-dimensional modeling of vertical Cl− concentration profiles in pore water revealed the upward flow of freshened groundwater within the pockmarks. The magnitude of submarine groundwater discharge (SGD) was estimated to vary from 1.53·10−2 to 18·10−2 L·m−2·h−1. The effect of groundwater seepage was also observed at 3 cm above the seafloor within the pockmarks, which was identified as a decrease in salinity of approximately 0.12 PSU compared to reference sites.Furthermore, due to the effect of water advection, SGD can be detected even several meters above the seafloor as a decrease in salinity values within the thermocline layer.

Apparent return of free-living Fucus vesiculosus to the Polish Baltic waters

The underwater meadows of the Puck Bay, once thriving with eelgrass Zostera marina, bladderwrack Fucus vesiculosus and black carrageen Furcellaria lumbricalis, experienced a decline in water quality during the 1960s and 1970s due to untreated sewage pollution. This, together with commercial exploitation, led to the disappearance of bladderwrack in 1977, with unsuccessful attempts at reintroduction in the early 2000s. In December 2023, a SCUBA survey near Rzucewo revealed a numerous bladderwrack in a benthic free-living form after 46 years of absence. The algae were found between 1.7 and 2.7 m depth, loosely positioned on the seabed, often within Z. marina beds, and with blue mussels Mytilus edulis attached. This reappearance suggests a positive trend in seawater quality and overall state of the Puck Bay, especially when combined with recent recovery of other algae species. The apparent return of bladderwrack could enhance ecosystem functionality, benefiting fish recruitment, grazer and algal biomass. Further investigations on bladderwrack's reappearance are needed in order to verify whether this is the only ecotype currently present in the Puck Bay.

Assessment of heavy metal concentrations and bioaccumulation in the invasive round goby (Neogobius melanostomus) and associated risks to human health

The round goby (Neogobius melanostomus) is an invasive species that can be used as a raw material in the food industry and also as a bioindicator of heavy metal pollution in the environment. In this study, Cd, Co, Cr, Mo, Ni, and Pb were determined in water, bottom sediment, muscle, liver, gills, and gonads of round goby from Dąbie Lake, Szczecin Lagoon, and Puck Bay (all in southern Baltic Sea) using atomic absorption spectrometry. Fulton’s condition factor, gonadal and hepatosomatic indices (GSI, HSI) were calculated. Based on estimated daily intake (EDI), target hazard quotient (THQ), and carcinogenic risk (CR), we assessed the human health risk related to the consumption of heavy metals in the round goby. The fish had length and weight ranges of 15.0–16.7 cm and 55.3–80.9 g, respectively. Fulton’s condition factor ranged from 1.26 to 2.48 and was highest (p < 0.05) for fish from Dąbie Lake. The range of metal concentrations (in μg kg−1) ranged from 2.92 (Cd in muscles of fish from Szczecin Lagoon) to 106.4 (Ni in muscles of fish from Dąbie Lake). The highest concentrations of Cd, Co, Mo, and Pb were found in livers, Ni in muscles and gonads, and Cr in gills. The calculated EDIs were below the reference oral dose (RfD) and maximum for Cd (1.6% RfD) and Pb (15.1% RfD). The hazard quotient was less than 1. In conclusion, the round goby has a higher potential to accumulate metals from water than from bottom sediments. Consumption of its muscle should not pose a health risk (cancer risk can be considered acceptable). Due to Pb accumulation, moderate consumption should be recommended for pregnant women and children. Finally, our results indicate that the round goby (especially its liver) can be used as a bioindicator to monitor metal contamination of aquatic ecosystems.

Microbial and chemical quality assessment of the small rivers entering the South Baltic. Part II: Case study on the watercourses in the Puck Bay catchment area

Microbial and chemical quality assessment of the small rivers entering the South Baltic. Part II: Case study on the watercourses in the Puck Bay catchment area

The benthic-pelagic coupling affects the surface water carbonate system above groundwater-charged coastal sediments

Submarine groundwater discharge (SGD) can be a significant source of dissolved nutrients, inorganic and organic carbon, and trace metals in the ocean and therefore can be a driver for the benthic-pelagic coupling. However, the influence of hypoxic or anoxic SGD on the carbonate system of coastal seawater is still poorly understood. In the present study, the production of dissolved inorganic carbon (DIC) and alkalinity (AT) in coastal sediments has been investigated under the impact of oxygen-deficient SGD and was estimated based on the offset between the measured data and the conservative mixing of the end members. Production of ATand DIC was primarily caused by denitrification and sulphate reduction. The ATand DIC concentrations in SGD decreased by approximately 32% and 37% mainly due to mixing with seawater counterbalanced by reoxidation and CO2release into the atmosphere. Total SGD-ATand SGD-DIC fluxes ranged from 0.1 to 0.2mol m-2d-1and from 0.2 to 0.3mol m-2d-1, respectively. These fluxes are probably the reason why the seawater in the Bay of Puck is enriched in ATand DIC compared to the open waters of the Baltic Sea. Additionally, SGD had low pH and was undersaturated with respect to the forms of the aragonite and calcite minerals of CaCO3. The seawater of the Bay of Puck also turned out to be undersaturated in summer (Inner Bay) and fall (Outer Bay). We hypoth​e​size that SGD can potentially contribute to ocean acidification and affect the functioning of the calcifying invertebrates.

Phenolic chemistry of the seagrass Zostera marina Linnaeus: First assessment of geographic variability among populations on a broad spatial scale

The variability of the phenolic content of thirteen populations of Zostera marina L. (six narrow-leaved and seven wide-leaved ecotypes) from different geographical zones, i.e., Baltic Sea, Mediterranean, East and West Atlantic, and East Pacific coasts was evaluated. Depending on the location, three to five phenolic acids and nine to fourteen flavonoids were identified of which an undescribed flavonoid sulfate. The phenolic concentrations of the thirteen populations differ among countries and among sites within countries. However, the same individuals were found almost everywhere. Substantial phenolic concentrations were found at all study sites with the exception of Puck Bay (Baltic Sea). Some geographical differences in the flavonoid content were observed. The highest phenolic diversity was found with specimens from the French Atlantic coast and the lowest with the Northeastern American sample (Cape Cod, MA). Regardless of their leaf width, the content of phenolic compounds was found to be similar and mainly characterized by rosmarinic acid and luteolin 7,3′-disulfate. The results demonstrate that geographic origin influences the phenolic composition of Z. marina primarily in terms of concentration, but not in terms of individual compound identity, despite the large geographic scale and the contrasting climatic and environmental conditions associated with it. This work is the first study to consider the spatial variability of phenolic compounds for a seagrass species on a spatial scale covering four bioregions. This is also the first to compare the phenolic chemistry of the two ecotypes of Z. marina.

Total mercury and methylmercury in garfish (Belone belone) of different body weights, sizes, ages, and sexes

BackgroundGarfish, (Belone belone) is a migratory pelagic fish that inhabits the waters of coastal Europe, North Africa, the North Sea, the Mediterranean Sea. Little information about garfish has been disseminated mainly because of its low abundance and its brief occurrence in various water bodies. Data is lacking on mercury compounds, particularly dangerous the toxic organic form of methylmercury (MeHg), which endangers the health of fish and their consumers. MethodsThe research material was garfish caught off the southern Baltic Sea coast in Puck Bay during the spawning period. Total mercury (THg) content was assayed with the cold vapour atomic absorption method in an AMA 254 mercury analyser. The MeHg extraction procedure was based on three-step sequential extraction method: hydrolysis using of hydrochloric acid, extract by toluene, bind the MeHg by L-cysteine. ResultsThe concentrations of THg and MeHg was determined in the muscle of garfish. The highest concentrations of THg (0.210 mg kg-1) and MeHg (0154 mg kg-1) were detected in the longest specimens (80 cm). The THg and MeHg concentrations in garfish muscles increased with specimens length, weight and age, which was confirmed by positive correlations. Differences were also noted depending on sex. Males accumulated more THg and MeHg than did females. The mercury in garfish from the southern Baltic Sea occurred mainly in its organic form MeHg and accounted for 84.7% of the THg. ConclusionSignificant differences were noted in mercury concentrations depends on length, weight, age and sex. Concentration of MeHg in garfish must be done by length class, and fish sex when selecting this fish for contamination studies and risk assessment. The toxic MeHg in garfish tissues did not pose a threat to the health of consumers, as indicated by the low values of EDI, TWI and THQ indices.

Genetic structure of pike (Esox lucius Linnaeus, 1758) populations along the Polish coast of the southern Baltic Sea: Comparison to Danish brackish population

The northern pike is a species of eco-evolutionary and socio-economic importance, originally freshwater but adapted to the conditions of brackish bays, lagoons and rivers flowing into seas. It was widespread along the entire coast of the Baltic Sea. A drastic decline in the stocks of Baltic pike in the 20th century caused large-scale stocking activities in the area, often based on non-native material from more abundant freshwater pike populations. Research into the genetic variation and structure of this species in the Baltic Sea is necessary as part of the key knowledge required for the management and conservation of the species. Applying eleven microsatellite markers, we analysed the genetic structure of 495 Baltic Sea pike sampled along the Polish coastal waters and including distant Danish population, collected in Præstø Fjord, in south-eastern Zealand Island. Using traditional F-statistics and a Bayesian approach we confirmed the presence of genetic structure within the analysed region. It was most likely the result of both evolutionary forces and anthropogenic factors. The analyses showed that genetic differentiation observed for the Danish and the others populations generally increased with the geographical distance, populations from the Puck Bay were distinct from the other, and the populations related to the Vistula delta and the Vistula itself form a strong common cluster. Our results contribute to current knowledge on the population genetics of Baltic Sea pike in a previously unstudied area and are in line with calls for on-going conservation, management and restoration activities for coastal Baltic pike to preserve existing genetic differences between different populations and avoid activities that potentially increase genetic homogenization.

Microbiological studies of the round goby (Neogobius melanostomus) from the Puck Bay, southern Baltic Sea.

In summer 2017 numerous dead round gobies ( Neogobius melanostomus) and individuals covered with white coating were observed in the Puck Bay. The aim of our research was to determine the microbiological composition of the round goby from the Puck Bay, focusing on the presence of pathogens. Bacteria were identified by biochemical methods and, by sequencing of 16S rRNA. The dominant bacterial species were Shewanella baltica, Pseudomonas spp. and Aeromonas spp. - opportunistic pathogens, commonly present in many fish species, which may become harmful for the organism in unfavorable conditions. It was the first trial to determine the composition of the bacterial flora of N. melanostomus from that area.

Goodbye to northern pike (Esox lucius) in the Polish southern Baltic?

This paper presents compilations of data on commercial fisheries catches of pike on the Polish coast and coastal lagoons in regard to pike stocking and some basic biological data gathered in 2010–2015 in Puck Bay. The decline in commercial pike catches in Polish coastal lagoons began as early as the 1950 s. In Puck Bay, where the species was the dominant predator, the causes of the rapid decline after the mid-1970 s were suggested to be the cut-off of spawning grounds in coastal wetlands and the depletion of underwater meadows. The stocking that has occurred thus far in Puck Bay has had an effect only when using summer fry (8–10 cm TL). In the fishermen’s opinion, restocking could be successful only if gillnet fishing was banned for at least 5 years and canals were unblocked for spawners.

Effects of beach wrack on the fate of mercury at the land-sea interface – A preliminary study

Since the 1970s, the amount of aquatic plants and algae debris, called beach wrack (BW), has increased along the shores of industrialised regions. The strong ability of primary producers to accumulate pollutants can potentially result in their deposition on the beach along with the BW. Despite that, the fate and impact of such pollutants on sandy beach ecosystems have not been investigated so far. This study examines the fate of neurotoxic mercury and its labile and stable fractions in BW on sandy beaches of the Puck Bay (Baltic Sea). In addition to BW, beach sediments and wrack-associated macrofauna were also analysed. Rough estimations showed that Puck Bay beaches (58.8 km) may be a temporary storage of 0.2–0.5 kg of mercury, deposited on them along with the BW annually. A large proportion of Hg (89 ± 16%) in a BW was labile and potentially bioavailable. The contribution of Hg fractions in the BW was conditioned by the degree of its decomposition (molar C:N:P ratio). With the progressive degradation of BW, a decrease in the contribution of Hg adsorbed on its surface with a simultaneous increase in the proportion of adsorbed (intracellular), mercury was observed. BW accumulation decreased oxygen content and redox potential and increased methylmercury content in underlying sediments, indicating methylation. Hg concentrations in the studied fauna were up to 4 times higher than in the BW. The highest values occurred in a predatory sand bear spider and the lowest in a herbivorous sand hopper. Regardless of trophic position, most of Hg (92–95%) occurred as an absorbed fraction, which indicates about a 30% increase in relation to its share of BW. These findings suggest the significant role of BW as a mercury carrier in a land-sea interface and increased exposure of beach communities to the adverse effects of mercury in coastal ecosystems.

Gone and Back—The Anthropogenic History of Coccotylus brodiei (Turner) Kützing and Furcellaria lumbricalis (Hudson) J.V. Lamouroux in the Gulf of Gdańsk (Southern Baltic Sea)

The Gulf of Gdańsk environment has supported the development and growth of the local community for centuries but has been significantly degraded as a result of the progressive eutrophication process that started in 1960, the extensive exploitation of marketable species (plants and fish) and pollution limiting the growth of marine organisms. Multistressors of the Anthropocene era have left their mark on all aspects of the ecosystem, but despite this, the gulf region has been considered to have exceptional environmental value and high biodiversity in comparison with adjacent regions. In 2004, a Natura 2000 site was created in the eastern part known as Puck Bay, and actions were taken to protect endangered habitats and species. Between 2019 and 2020, intensive field studies were conducted in Puck Bay on flora to assess biodiversity and habitat resources. The material was collected for qualitative and quantitative analysis. This allowed observation of species that have not been reported since the 1970s, i.e., Coccotylus brodiei (Turner) Kützing and Furcellaria lumbricalis (Hudson) J.V. Lamouroux. Both species co-occurred as in the period before the 1960s in the form of free-floating thalli. The rediscovery of these taxa suggests that despite very unfavourable conditions for their development due to anthropogenic pressures, they were able to survive, and their occurrence throughout Puck Bay indicates improvement in environmental quality due to declining human impact. Our results indicate that benthic algal communities have high regeneration potential, but in the case of severe environmental degradation caused by synergistic pressures of high intensity, plant recovery without measures to support remediation takes at least 30 years.

Are we ready to implement resist–accept–direct framework thinking? A case study of fish stocks and small‐scale fisheries in the Puck Bay (Southern Baltic)

AbstractThe Puck Bay socioecological system is covered by many management plans, most of which are embedded in a paradigm of resistance to ecosystem change. However, it is highly probable that this system has already passed the tipping point, in terms of both the availability of fish stocks and small‐scale fishery function in coastal communities. The current scheme excludes the listing of alternative management options, as it rejects those that have not been agreed upon. Societal feasibility has been a barrier to many of these rejected solutions. Another problem is the low level of coordination between the plans and the varying ability to implement them, which depends on the funding source. Recognising that the ecosystem is in transition and may not be controllable, managers can apply the resist–accept–direct (RAD) framework to make more informed decisions and better prepare for the future.

Long-term stability of diclofenac and 4-hydroxydiclofenac in the seawater and sediment microenvironments: Evaluation of biotic and abiotic factors

Studies in recent years have shown that significant amounts of diclofenac (DCF) and its metabolites are present in marine coastal waters. Their continuous flow into the environment may be associated with numerous negative effects on both fauna and flora. Although more and more is known about the effects of pharmaceuticals on marine ecosystems, there are still many issues that have not received enough attention, but are essential for risk assessment, such as long term stability. Furthermore, interaction of pharmaceuticals with sediments, which are inhabited by rich microbial, meiofaunal and macrobenthic communities need investigation. Therefore, we undertook an analysis of the stability of DCF and its metabolite, 4-hydroxy diclofenac, in seawater and sediment collected from the brackish environment of Puck Bay. Our 29-day experiment was designed to gain a better understanding of the fate of these compounds under experimental conditions same as near the seafloor. Diclofenac concentration decreased by 31.5% and 20.4% in the tanks with sediment and autoclaved sediment, respectively during 29-day long experiment. In contrast, the concentration of 4-OH diclofenac decreased by 76.5% and 90.2% in sediment and autoclaved sediment, respectively. The concentration decrease of both compounds in the sediment tanks resulted from their sorption in the sediment and biodegradation. Obtained results show that marine sediments favour DCF and 4-OH DCF removal from the water column.

Natural and social science approaches are both needed to manage bird bycatch in small‐scale fisheries

Abstract Puck Bay is one of the most important resting and wintering places for seabirds in the Baltic Sea. It is also an important, intensively used fishery ground for traditional small‐scale fisheries operating with gillnets. The protection measures proposed in the consultation for the Natura 2000 Puck Bay conservation plan encountered considerable resistance from small‐scale fishermen. The most serious problem was the gap in scientific knowledge and the proposed closure of gillnets in a substantial area of the bay for the period from November to April. The conditions of bird bycatch in Puck Bay for the period from 1 October 2014 to the end of April 2015 are considered from two perspectives: modelling of bycatch data collected during pilot monitoring by direct on‐board observation together with voluntary fishery logbooks and content analysis of fishermen's interviews. The results from both attempts indicate that solutions to minimize bird bycatch should be sought for winter (December–February) and for all net types. Bycatch is also influenced by depth and fishing area. The modelling results indicate that fishing time is also important. The bycatch in Puck Bay between October 2014 and April 2015 was estimated at 1,332 birds (95% confidence interval: 789–2,898). The estimation was subject to additional uncertainty due to quantitative data limitations. In conflicting situations that require fisheries management to protect the environment, the use of fisheries knowledge through social science methods is essential. The barrier to such interdisciplinary research seems to be a lack of trust not only between fishermen and scientists but also between natural and social scientists. Fishery management in Puck Bay should be based on the combination of continuous bird and bird bycatch monitoring with the integration of local fishery knowledge to minimize the scale of bycatch.

A recently discovered wreck with double planking in the Bay of Puck. Measurements, recording and positioning of the site with the use of a 3D photogrammetry model and a multibeam echosounder

The F32.8 wreck was discovered in 2014 at a depth of 4.5 m in the waters of the Bay of Puck, Poland. The wreck consists of a fragment of the port side of a vessel with a characteristic double, clinker and carvel, planking. The site is 9.5 m long and 2.8 m wide. The wreck is composed of pine strakes for the outside carvel planking; levelling pine strakes, triangular in a cross section; oak strakes for the inside clinker planking; oak frames; pine treenails of three different diameters. The vessel was built after 1789 with wood from the region of Norway.

Characteristics of morphodynamic conditions in the shallows of Puck Bay (southern Baltic Sea)

Abstract Puck Bay is an unusual and thus interesting coastal water region, as it combines two different environments – a lagoon and the sea. They differ from each other in their seabed morphology, salinity, dynamics and water exchange. Their common elements are the extensive shallows and the vicinity of the Hel Peninsula. The shallows of Puck Bay have developed at various stages of its evolution, which began several thousand years ago and continues to this day. They have been shaped by varying morphogenetic factors resulting from changes in sea level and accompanying evolution phases of sand barriers, e.g. washover fans, as well as the intensity and directions of sediment transport. At present, the shallows cover more than 35% of the seabed area and are influenced by hydrodynamic factors and availability of sediments. The study area was divided into five fields, taking into account morphological and genetic criteria as well as recent hydrodynamic conditions. This study provides an updated map with classification and distribution of surface sediments and describes grain size parameters for sediment samples collected in the selected fields. Based on a comprehensive assessment of grain size parameters, lithodynamic equilibrium zones were determined and areas of sediment deposition and redeposition were identified.

Distribution and extent of benthic habitats in Puck Bay (Gulf of Gdańsk, southern Baltic Sea)

The majority of the southern Baltic Sea seabed encompasses homogenous soft-bottom sediments of limited productivity and low biological diversity, but shallow productive areas in the coastal zone such as wetlands, vegetated lagoons and sheltered bays show a high variety of benthic habitat types offering favourable biotopic conditions for benthic fauna. Within Polish marine areas, semi-enclosed Puck Bay (the western part of the Gulf of Gdańsk) features an exceptionally diverse environment covering a range of benthic habitats which underscores its unique biological value and aesthetic quality and providing an impetus for conservation and ecosystem-based development. Full-coverages maps on benthic habitats in this area are therefore a necessary foundation for maritime spatial planning and implementation of strategies for sustainable management and protection of the coastal environment. This study presents the first comprehensive description and distribution of benthic habitats in Puck Bay which were categorised using the revised EUNIS 2019 classification system. Typological analyses were carried out based on inventory datasets from 1995 to 2019 including scientific publications, satellite images, open databases, topographic and geological maps, reports, theses, information available on websites and unpublished data shared willingly by individual researchers and administrative institutions. Collating various spatial data sources, that were first georeferenced and then visualized using techniques available in ArcMap 10.4.1 software (Esri), resulted in the mapping of benthic habitats and sites of important and protected plant species, which can contribute to the high confidence in environmental assessments and monitoring activities.

Seasonal changes in body size and mass of Red Knots Calidris canutus during autumn migration through southern Baltic

Body size and mass of 1,458 juvenile and 558 adult Knots were measured during autumn migration in Puck Bay, Poland, between 1983 and 1999. The measurements fit well with those gathered along the migration route of Siberian Knots Calidris c. canutus. All linear measurements of adults, except body mass adjusted for size, were significantly higher than those of juveniles. Shorter wing in juveniles than in adults seems to be a general rule regardless of geographical region. Adult females migrated ahead of males, confirmed by decreasing mean measurements. Juveniles carried larger relative energy stores than adults. Puck Bay may be an emergency feeding place for adult Knots, whereas juveniles may use it as one of many stop-over sites. Juveniles were significantly smaller, but had higher adjusted body mass, in late September than earlier, indicating a behavioural difference between late and early birds during preceding stages of migration. Late juveniles probably follow a time-minimising strategy with larger fuel stores and fewer stop-over sites, whereas birds passing in August migrate with very small energetic reserves, making only short flights and stops.