Southern Sea Research Articles

Phytoplankton composition associated with physical and chemical variables during summer in the southern sea of Korea: Implication of the succession of the two toxic dinoflagellates Cochlodinium (a.k.a. Margalefidinium) polykrikoides and Alexandrium affine

Harmful algal blooms (HABs) of the dinoflagellates Cochlodinium and Alexandrium are known to have serious negative impacts on marine ecosystems and the aquaculture industry. We investigated the appearance and succession patterns of both HAB species in the southern sea of Korea and performed a bioassay using C.polykrikoides and A.affine cultures to evaluate their competitive relationship. From June to August in 2017, the surface water temperature increased from 17.4 °C to 26.8 °C, the salinity decreased from 34.2 to 30.8, and strong stratification developed. The nutrient concentrations remained low in the surface layer and high in the bottom layers. C.polykrikoides dominated in July; however, A.affine reached bloom levels throughout the study area in August. The growth experiments were carried out on each species at six water temperature (15, 20, 22.5, 25, 27.5 and 30 °C) and six salinity (20, 24, 26, 28, 30 and 32) levels. The maximum growth rate for C. polykrikoides (0.31 day−1) was measured at 25 °C and a salinity of 32, and for A. affine (0.43 day−1) at 25 °C and a salinity of 30. At all salinity levels, C. polykrikoides cells died within 2 days when temperature were 30 °C, while A.affine maintained high growth rates (0.35–0.39 day−1). Further, C. polykrikoides is salinity sensitive at the lowest salinity level of 20 in 25 °C and 27 °C, but A. affine did not respond sensitively to changes in salinity. In contrast, A. affine did not grow at low temperature of 15 °C, but C. polykrikoides could survive in high salinity range (26–32). In co-cultivation at a 1:1 cell inoculation ratio, A.affine had a competitive advantage over C. polykrikoides at all temperatures; however, when the inoculation ratios were varied, the species with a higher initial cell density showed a competitive advantage at all temperatures except 30 °C. Combined the field and bioassay results indicated that A. affine may have an advantage over C. polykrikoides under relatively higher temperature and low salinity conditions, which is important when evaluating the species succession and blooms in the southern sea of Korea during summer.

Non-trophic impacts from white sharks complicate population recovery for sea otters.

Complex interactions between protected populations may challenge the recovery of whole ecosystems. In California, white sharks (Carcharodon carcharias) mistargeting southern sea otters (Enhydra lutris nereis) are an emergent impact to sea otter recovery, inhibiting the broader ecosystem restoration sea otters might provide. Here, we integrate and analyze tracking and stranding data to compare the phenology of interactions between white sharks and their targeted prey (elephant seals, Mirounga angustirostris) with those of mistargeted prey (sea otters, humans). Pronounced seasonal peaks in shark bites to otters and humans overlap in the late boreal summer, immediately before the annual adult white shark migration to elephant seal rookeries. From 1997 to 2017, the seasonal period when sharks bite otters expanded from 2 to 8 months of the year and occurred primarily in regions where kelp cover declined. Immature and male otters, demographics most associated with range expansion, were disproportionately impacted. While sea otters are understood to play a keystone role in kelp forests, recent ecosystem shifts are revealing unprecedented bottom‐up and top‐down interactions. Such shifts challenge ecosystem management programs that rely on static models of species interactions.

The Effect of Temperature, Salinity and Irradiance on the Growth of <i>Alexandrium affine</i> (Dinophyceae) Isolated from Southern Sea of Korea

The Effect of Temperature, Salinity and Irradiance on the Growth of <i>Alexandrium affine</i> (Dinophyceae) Isolated from Southern Sea of Korea

Амфоры типа 27 по классификации В.В. Крапивиной из Тиры

В научный оборот вводятся находки амфор типа 27 по классификации В.В. Крапивиной, обнаруженные при исследовании Тиры. Уделяется внимание вопросам их морфологии и хронологии, указываются визуальные особенности керамического теста, характерные для исследуемой разновидности амфорной тары. Определяется ареал распространения таких сосудов. Выдвигается предположение о том, что рассматриваемые амфоры предназначались для транспортировки соленой рыбы и поступали в Тиру с территории Боспора на протяжении III в. н.э.

A Geomorphological Evaluation of Sea Turtles Nesting in the Southern Sea of West Java

Sea turtles are reptile that classified to the ‘red list’ at IUCN and Appendix I CITES. It means that their existence in nature has been threatened by a human, predator, and climate changes, so it should be conserved. Among various species of sea turtles, most of them laid their eggs in the coastal area of Indonesia, likely in Java Island. Under these conditions, this research is going to evaluate the condition of coastal areas where turtles laid their eggs in some part of the southern sea of Java Island based on geomorphological approach. Batu Hiu and Pangumbahan coastal area, West Java took for sampling area. The characteristics of geomorphology that affect turtle nesting habitats including its morphology, sand material, and coastal processes. Those aspects divide into the beach slope, beach wide, beach length, grain-size, wind parameters, waves parameters, and vegetation as an additional aspect. Based on those measurements, the coastal geomorphology characteristic on two sampling sites used as a standard evaluation for sea turtles nesting. Identification on beaches along the southern sea of west Java found that there are nine potential locations with the same characteristic with Batu Hiu and Pangumbahan coastal area as turtle nesting habitats.

Pathology and epidemiology of nasopulmonary acariasis (Halarachne sp.) in southern sea otters (Enhydra lutris nereis).

Halarachne sp. nasal mites infest harbor seals (Phoca vitulina) and southern sea otters (Enhydra lutris nereis) in California, but little is known about the pathophysiology of these infestations, or risk factors for exposure. To investigate these questions, a retrospective case-control study was performed using necropsy data from 70 mite-infested sea otters, and 144 non-infested controls. Case records for sea otters examined by pathologists from February 1999 through May 2015 were examined to assess risk factors for infestation, and lesions associated with nasopulmonary acariasis. Animals with a history of captive care within 10 days of death or carcass recovery were 3.2 times more likely to be infested with nasopulmonary mites than those with no history of recent rehabilitation. Sea otters stranding within 1 km of Elkhorn Slough in Monterey Bay were 4.9 times more likely to be infested with nasal mites than other areas; this site is characterized by high sea otter contact with sympatric harbor seals (a common host for Halarachne sp.), and a comparatively large population of rehabilitated and released sea otters. Aged adult otters were 9.4 times more likely to be infested than younger animals, and sea otters with nasopulmonary acariasis were 14.2 times more likely to have upper respiratory inflammation than un-infested animals. Additional findings in otters with nasopulmonary acariasis included lower respiratory tract bacterial infections, presence of medium-sized and/or fresh nose wounds at necropsy (indicators of recent face-to-face interaction between otters during copulation or fighting), and turbinate bone erosion. Our findings, although preliminary, suggest that captive rehabilitation and close contact with harbor seals could facilitate nasopulmonary mite transmission to sea otters. We also identified a high-risk zone for nasopulmonary acariasis in sea otters. We also provide preliminary data to suggest that nasopulmonary mite infestations can cause significant respiratory pathology in sea otters.

First observation on the diet and feeding strategy of cloudy catshark Scyliorhinus torazame (Tanaka, 1908)

Dietary studies of elasmobranch species are an essential component for developing management and conservation frameworks, because of their ecological importance as top predators in coastal marine ecosystems. The diets of cloudy catshark Scyliorhinus torazame were studied with the aid of 117 specimens collected from the southern sea of Korea. S. torazame was mainly piscivorous, but also ingested polychaetes and small amounts of benthic crustaceans. This dietary composition led to an estimated trophic level of 3.9 for the species. The diets of S. torazame changed significantly with season, but not length or sex of the sharks. Graphical analysis indicated that S. torazame is a benthic generalist feeder that consumes a variety of prey, but also showed high individual diet specialization.

Global Distribution of Omura’s Whales (Balaenoptera omurai) and Assessment of Range-Wide Threats

When the Omura’s whale (Balaenoptera omurai) was first described in 2003, it was known from only three locations: the southern Sea of Japan, and the vicinities of the Cocos (Keeling) Islands and Solomon Islands. Work over the following decade suggested a range limited to the Indo-Pacific, but more recent discoveries in the western Indian Ocean and Atlantic Ocean suggested a more widespread range than previously thought. Here we use all available sources of information, including published papers, unpublished reports, and web-based accounts, substantiated through genetic, morphological, photographic and acoustic documentation, to complile accounts of Omura’s whales globally. Reports increased precipitously since 2015 after publication of the first detailed external description of the species, reflecting the impact of the recently elevated awareness of the species. We report 161 accounts from 26 locales in the waters of 21 range states, and found that the species is widely distributed in primarily tropical and warm-temperate locations. Currently it is known from all ocean basins with the exception of the central and eastern Pacific. The majority of accounts remain in the eastern Indo-Pacific suggesting a potentially recent range expansion from this region. There is a strong tendency towards a coastal and neritic distribution, although there are also several pelagic records. A predominantly near coastal distribution places Omura’s whale at risk from anthropogenic activities throughout its range, and its tropical distribution in often remote and poorly monitored areas makes adequately documenting and assessing threats challenging. We assess documented threats in light of the reported species’ range, and found threats from, at minimum, ship strikes, fisheries bycatch and entanglement, local directed hunting, petroleum exploration (seismic surveys), and coastal industrial development. Current evidence indicates that at least some populations are non-migratory with local, potentially restricted ranges. Furthermore, there is low genetic diversity documented throughout its global distribution. Given the species may be characterized by small local populations, it may be particularly vulnerable to impacts from existing regional anthropogenic threats. We recommend that focused work be conducted to locate and study local populations, assess potential population isolation, and determine conservation status and specific anthropogenic threats across the species’ range.

Solving a long-standing nomenclatorial controversy: designation of a neotype for the southern sea lion Otaria flavescens (Shaw, 1800)

During almost two centuries, two available specific epithets have competed for the southern sea lions of the genus Otaria Péron, 1816 (Fig. 1), which is classically regarded as monotypic (but see below). The species distributes more or less continuously along the Atlantic coast from southern Brazil south to Cape Horn and along the Pacific from northern Peru to the west South American Pacific coast . While some researchers have argued that the correct name for this species is Phoca flavescens Shaw, 1800 (e.g., Cabrera, 1940, Rice, 1977; Rodriguez Bastida, 1993; Teta et al., 2018), others have used P. byronia de Blainville, 1820 (e.g., Allen, 1905; Hamilton, 1934; King, 1978, Oliva, 1988; Berta Churchill, 2012). This controversy originates from the fact that the diagnosis of the type of flavescens, the oldest epithet and as such the one that has priority, would not match the phenotypic features of the genus Otaria. This view, which favors the usage of byronia for populations of southern sea lions, was strongly defended by Oliva (1988:768), who argued that "…(1) the total length of the holotype [of flavescens]; (2) the size of the external ear; and (3) the color and length of the specimen's fur do not correspond to any developmental stage of the species." However, Rodríguez and Bastida (1993:378) discussed these same features reaching a very different conclusion, by indicating that "Shaw's holotype, collected in the Strait of Magellan, could only have been a newborn pup of Otaria or Arctocephalus australis; its body size (circa 62 cm) could correspond to either species, but the uniform yellowish color is found exclusively in some molted pups of the Southern sea lion. Ear length, though not matching well with the described body length, lies within the recorded range of Otaria, but outside that for Arctocephalus australis."

New records of benthic harpacticoids from Korea: I. Three new species of the genus Zosime Boeck (Copepoda: Harpacticoida: Zosimeidae)

ABSTRACTTaxonomic studies of benthic harpacticoids from sublittoral habitats in the Southern Sea of Korea were performed. Three new species belonging to the genus Zosime Boeck, 1873 were discovered: Zosime comata sp. nov., Z. changi sp. nov., and Z. gymnokosmosa sp. nov. They all belong to the typica group, which is characterized by diagnostic female features of a mandibular exopod with three setae, leg 5 fused with baseoendopod bearing an exopodal seta arising from the anterior surface, and elongate caudal rami with a length more than 1.6 times its width. These three new species unusually have only two outer spines on the distal exopodal segments of legs 1–4, a character is unique in the genus except for Z. bathyalis Por, 1967, in contrast to the three outer spines on the corresponding segments in other congeners. However, the three new species can be distinguished from Z. bathyalis and each other by body ornamentation, segmentation of the female antennule, setation of the distal endopodal segment on legs 2–4, and an endopodal lobe on leg 5 in both sexes. Detailed descriptions and illustrations of these three new Zosime species are provided.

Late Pleistocene and Holocene occurrence of bowhead whales (Balaena mysticetus) along the coasts of Norway

The present study aims at an improved understanding of the origin and distribution of bowhead whales (Balaena mysticetus) along the Norwegian coast during Late Pleistocene/Holocene. We used ancient DNA methodology to identify the species of 52 large whale bones found along the coast of the Norwegian mainland. Nucleotide sequence variation of the mitochondrial control region (CR) was determined and subsequently screened against GenBank for species identification. Thirty-one bones (60%) yielded informative nucleotide sequences for the targeted mitochondrial CR. Of these, 24 matched with bowhead whale. Two additional bones were identified to bowhead whale based on morphology. Thus, 26 of the bones were identified to be from bowhead whales. The ages of the bowhead bones ranged from 15,084 cal years BP to present, with most bones older than 10,000 cal years BP. We suggest that our results show a change in distribution of bowhead whales from the very southern Norwegian Sea in the Heinrich Stadial 1 (19,000–14,600 years BP) to a distribution reaching 64°N in the Bolling–Allerod Interstadial (14,600–12,900 years BP), while the species probably was absent along the Norwegian coast during the cold Younger Dryas (12,900–11,700 years BP). During the Holocene, the species most likely has had only a northern distribution. The present study does not contribute new knowledge to solve the question if North Atlantic bowhead whales originated from a refugium in the southeast Atlantic during the Last Glacial Maximum or originate from the Pacific.

Refugee Crisis and Migrations at the Gates of Europe: Deterritoriality, Extraterritoriality and Externalization of Border Controls

Refugee Crisis and Migrations at the Gates of Europe: Deterritoriality, Extraterritoriality and Externalization of Border Controls

Occurrence characteristics of harmful and non-harmful algal species related to coastal environments in the southern sea of Korea

Because the phytoplankton community and blooms are regulated by various environmental factors, it is difficult to define the cause and occurrence of the phenomenon of harmful algal blooms (HABs). This study evaluated the phytoplankton community and occurrence characteristic of HAB species related to coastal environments in South Korea, 2016. In summer, because of strong upwelling event, the surface sweater temperature around Geoje Island was abnormally low (17°C), and an unusual high temperature (29°C) and low salinity (29psu) were measured in offshore area. Diatoms and dinoflagellates showed contrasting occurrences during the survey period. Diatoms were dominant in the inshore area, whereas dinoflagellates occurred in the offshore area. The phytoplankton-community structures were established depending on different hydro-oceanographic characteristics. In statistical analysis, HABs of dinoflagellate Karenia appeared in upwelling areas with a high nutritional content, whereas Gymnodinium, Gyrodinium and Prorocentrum appeared in areas of low nutrients in June, and HAB species showed an equivalent tendency to appear at high water temperature and low saline level in August. Our results indicated that hydro-oceanographic events such as river discharge, current and upwelling play important roles in determining the phytoplankton community and potential occurrence characteristics of HABs in the coastal environment of South Korea.

Entre el mito y la realidad. La situación de la misteriosa Isla Elizabeth de Francis Drake

In 1578, after a calm navigation through the Strait of Magellan, the English sailor Francis Drake had to face the furies of the South Pacific Ocean for almost two months. In one of his forced derivations the endless storm that punished his ship took him deep into the stormy southern sea, circumstance in which he and his companions found an island called Elizabeth fixing its approximate position. That island would never again be sighted by any sailor until now. Posterity has accepted this observation and has sought an explanation for its disappearance attributing it to the dynamics of the earth’s crust, which in turn causes variations in the ocean floor. About the same is reported about the progressive knowledge of submarine relief in the Drake Sea area south of the Diego Ramirez Islands, where the Sars submarine mount has recently been found, an abyssal elevation as interesting as suggestive for further scientific studies referring to the interconnection of Antarctica and South America in remote geological times.

Records of Southern Sea Lion (Otaria flavescens) (Mammalia: Carnivora: Otariidae) and Total Mercury (THg) Levels in Muscle Tissue of a Specimen on the East Coast of Rio de Janeiro State, Southeastern Brazil

This study aims to present records of southern sea lions (Otaria flavescens) on the coast of Arraial do Cabo, located on the east coast of Rio de Janeiro State, southeastern Brazil, and information on the levels of total mercury (THg) found in muscle tissue of a specimen collected in the study area. Between July 2003 and February 2017, 5 occurrences of southern sea lions were recorded in the study area. Four of these records were of live animals, while one was of a carcass in advanced state of decomposition. In relation to the concentrations of THg found in the muscle tissue of the analyzed individual, they ranged from 0.047 to 0.067 mg/kg, with a mean value found of 0.057 mg/kg, a standard deviation of 0.010 and a coefficient of variation of 17.5%.

Mycoplasma enhydrae sp. nov. isolated from southern sea otters (Enhydra lutris nereis).

Five Mycoplasma strains have been isolated from the oropharynx of southern sea otters (Enhydra lutris nereis) from the Central California Coast, USA. These strains were phenotypically and genetically characterized and compared to other established Mycoplasma species. All five strains hydrolysed arginine but not urea, but did not produce acid from glucose, and all were isolated and propagated under anaerobic and aerobic atmospheric conditions at +35-37 ˚C using either SP4 or PPLO medium supplemented with arginine. Colonies on solid medium showed a typical fried-egg appearance and transmission electron microscopy revealed a typical mycoplasma cellular morphology. Molecular characterization included assessment of the following genetic loci: 16S rRNA, 16S-23S rRNA ITS, rpoB, rpoC, polC, topIIA, tufB, arcA and smc. Complete 16S rRNA gene sequence analysis indicated that these strains were most closely related to M.ycoplasma phocicerebrale, and to M.ycoplasma arginini, M.ycoplasma gateae and M.ycoplasma canadense with nucleotide similarities of 99 and 98 %, respectively. Nucleotide analysis of other genetic loci revealed 73-91 % nucleotide similarity to the corresponding genes of the above closely related species. All five strains clustered into a distinct group on the 16S rRNA and rpoB phylogenetic trees. Serological testing via growth inhibition and metabolic inhibition tests employing antiserum to type strains of M. phocicerebrale, M. arginini, M. gateae and M. canadense failed to recognize these novel strains. Our results suggest that the strains isolated from southern sea otters represent a novel species of the genus Mycoplasma, for which the name Mycoplasma enhydrae sp. nov. is proposed; the type strain is 6243-11T (=DSM 106704T=ATCC TSD-140T).

Religiusitas Gunung Merapi

The concept of 'manunggaling kawula gusti', which had developed in Java in ancient times, until now still colored the behavior of people living around Mount Merapi, which among others demanded the full devotion of the people to the Sultan and his magical companions, namely Baurekso Mount Merapi and Nyi Rara Kidul in the southern sea. Mbah Marijan and some of her descendants and followers still show loyalty, so in order to keep their Merapi they offer to the Sultan as the ruler of the human world, which is often regarded as the incarnation of Gods / Lords of the rulers of the universe. In this way they believed that their spirits would later merge with Gusti as their worship, as a form of uniting the people's physical body to the king and to rule over nature. The purpose of this study is to find out more about the meanings contained in Mount Merapi, namely the mountain that is feared and sacred by the people of Yogyakarta, and especially those who live on the slopes of Merapi.

Genetic Distances in Two Gracilaria Species (Gracilariaceae, Rhodophyta) Identified by PCR Technique.

Genomic DNA was isolated from the Gracilaria vermiculophylla (GRV) and G. chorda (GRC) from Jangheung located in the southern sea of the Korean Peninsula, respectively and we performed clustering analyses, DNA polymorphisms and the genetic differences. The seven selected primers OPC-01, OPA-04, OPA-05, OPD-07, OPD-08, OPB-10, and OPD-16 generated average bandsharing (BS) value, the genetic distance and dendrogram. The size of DNA bands varies from 90 bp to 2,400 bp. The average BS value was 0.859±0.004 within GRV and 0.916±0.006 within GRC. The average BS value between two Gracilaria species was 0.340±0.003, ranged from 0.250 to 0.415. The dendrogram obtained by the seven primers, indicates two genetic clusters. The genetic distance between two Gracilaria species ranged from 0.059 to 0.513. The individual VERMICULOPHYLLA no. 07 of GRV was genetically closely related to VERMICULOPHYLLA no. 06 of GRV (genetic distance=0.059). Especially, two entities between the individual VERMICULOPHYLLA no. 10 of GRV and CHORDA no. 22 of GRC showed the longest genetic distance (0.513) in comparison with other individuals used. Accordingly, as mentioned above, PCR analysis showed that the GRV was a little more genetically diverse than the GRC species. We convinced that this DNA analysis revealed a significant genetic distance between two Gracilaria species pairs (p<0.01).

Deep-sea ostracod faunal dynamics in a marginal sea: biotic response to oxygen variability and mid-Pleistocene global changes

AbstractDeep-sea benthic ostracod assemblages covering the last 2 Myr were investigated in Integrated Ocean Drilling Program Site U1426 (at 903 m water depth) in the southern Sea of Japan. Results show that (1) orbital-scale faunal variability has been influenced by eustatic sea-level fluctuations and oxygen variability and (2) secular-scale faunal transitions are likely associated with the mid-Brunhes event (MBE, ~0.43 Ma) and the onset of the Tsushima Warm Current (TWC, ~1.7 Ma).Krithe,Robertsonites, andAcanthocythereisare the three most abundant genera throughout the core, accounting for 78.5% of total specimens. Multiple-regression tree analysis indicated that the TWC, the MBE, and oxygen content are the significant controlling factors of ostracod dominance. Changes in assemblages exhibit decline and recovery patterns corresponding to orbital-scale cyclicity of sea-level changes. In the Sea of Japan marginal ocean setting, this cyclicity shows a close relationship with bottom-water oxygen variability since the onset of the TWC influx. The MBE amplified the influence of the TWC and oxygen variability to the deep-sea ecosystem through larger sea-level fluctuations.Acanthocythereis dunelmensis, a circumpolar species, dominates before the TWC onset. After the TWC onset and during the mid-Pleistocene transition (MPT, ~1.2–0.7 Ma)Krithespp., known for their low-oxygen tolerance, substantially increase under moderate oxygen depletion. At the end of the MPT,Krithedominance diminishes and is replaced byRobertsonites hanaiiandPropontocyprisspp. after the MBE. The post-MBE assemblage, characterized byR. hanaii, suggests a slightly warmer environment under the development of the TWC. In addition, the post-MBE high-amplitude climate system may have caused the increased abundance of active-swimmingPropontocyprisspp. due to their superior migration ability. Benthic ecosystems in marginal seas are sensitive and vulnerable to both short- and long-term climatic changes, and the MBE is suggested to be a global biotic event affecting benthic ecosystems substantially.

Living on the edge: thermoregulatory behaviour of South American sea lions, Otaria flavescens, at the northern limit of their Atlantic distribution

Terrestrial reproduction presents a thermoregulatory challenge for marine mammals, especially in a context of global warming. Pinnipeds, especially otariids, differ from other marine mammals in that most reproductive processes occur on land. Rocky rookeries rarely provide thermoregulatory resources (shade, pools and wet sand), so pinnipeds reduce thermal stress through thermoregulatory behaviour such as flipper exposure, flipper movement and maintenance of individual distance. Our objective was to analyse climate correlates of thermoregulatory behaviour of Southern sea lions Otaria flavescens in a colony located at the warmest end of its northern distribution on the Atlantic coast of South America. We conducted summer behavioural observations of juveniles/sub-adult (less than 150 kg) and adult (300 kg) males in the Cabo Polonio rookery, Uruguay. Solar radiation and humidity were positively correlated with thermoregulatory behaviour of sea lions, while ambient temperature had a marginal effect and wind speed had no significant effect. There were no statistically significant differences between age classes in thermoregulation activity. These and previous results on thermoregulatory behaviour of pinnipeds open the possibility that pinnipeds can be limited in abundance or distribution if climate change alters solar radiation in terrestrial rookeries during the breeding season.