The effect of anthropogenic substrate-borne vibrations on locomotion of the fiddler crab Austruca lactea.

The anthropogenic construction activities on the coasts, such as pile-driving, generate vibrations that propagate through the substrate. Such substrate-borne vibrations could potentially affect marine organisms inhabiting the benthic environments. However, there is a lack of documented studies on the effects of vibrations on benthic animals.

Archival records of the Antarctic clam shells from Marian Cove, King George Island suggest a protective mechanism against ocean acidification.

Continuous emissions of anthropogenic CO are changing the atmospheric and oceanic environment. Although some species may have compensatory mechanisms to acclimatize or adapt to the changing environment, most marine organisms are negatively influenced by climate change. In this study, we aimed to understand the compensatory mechanisms of the Antarctic clam, Laternula elliptica, to climate-related stressors by using archived shells from 1995 to 2018.

Reduction-Responsive Chitosan-Based Injectable Hydrogels for Enhanced Anticancer Therapy.

Selective delivery of anticancer drug molecules to the tumor site enhances local drug dosages, which leads to the death of cancer cells while simultaneously minimizing the negative effects of chemotherapy on other tissues, thereby improving the patient's quality of life. To address this need, we developed reduction-responsive chitosan-based injectable hydrogels via the inverse electron demand Diels-Alder reaction between tetrazine groups of disulfide-based cross-linkers and norbornene groups of chitosan derivatives, which were applied to the controlled delivery of doxorubicin (DOX). The swelling ratio, gelation time (90-500 s), mechanical strength (G'~350-850 Pa), network morphology, and drug-loading efficiency (≥92%) of developed hydrogels were investigated.

The effect of molecular weight and chemical structure of cross-linkers on the properties of redox-responsive hyaluronic acid hydrogels.

In this work, we investigated the effect of the size and the chemical structure of crosslinkers on the properties of hyaluronic acid-based hydrogels prepared via an inverse electron demand Diels-Alder reaction. Hydrogels having loose and dense networks were designed by cross-linkers with and without polyethylene glycol (PEG) spacers of different molecular weights (1000 and 4000 g/mol). The study showed that the properties of hydrogels such as swelling ratios (20-55 times), morphology, stability, mechanical strength (storage modulus in the range 175-858 Pa), and drug loading efficiency (87 % ~ 90 %) were greatly influenced by the addition of PEG and changing its molecular weight in the cross-linker.

Microplastics in large marine animals stranded in the Republic of Korea.

Microplastics (MPs) are found in every ocean and are frequently ingested by marine animals. This study analyzed MPs in the stomachs and intestines of 12 large marine animals comprising one fin whale (Balaenoptera physalus), seven finless porpoises (Neophocaena asiaeorientalis), two loggerhead turtles (Caretta caretta), one Indo-Pacific bottlenose dolphin (Tursiops aduncus), and one common dolphin (Delphinus delphis) that were stranded off the Republic of Korea between 2019 and 2021. MPs were detected with a mean abundance of 3.

NIR-degradable and biocompatible hydrogels derived from hyaluronic acid and coumarin for drug delivery and bio-imaging.

In this work, bioorthogonal and photodegradable hydrogels derived from norbornene (Nb) functionalized hyaluronic acid and a water soluble coumarin-based cross-linker possessing terminal tetrazine (Tz) groups, were developed for NIR-responsive release of doxorubicin (DOX). The inverse electron demand Diels-Alder cross-linking reaction between Nb and Tz functionalities formed the hydrogels at physiological conditions, whereas N gas liberated during the reaction created pores in the hydrogels. The gelation time ranges (about 5-20 min) and the viscoelastic behavior (G' ~ 346-1380 Pa) demonstrated that the resulting hydrogels were injectable and possessed tunable mechanical properties.

Possible link between derelict fishing gear and sea turtle strandings in coastal areas.

Ghost fishing via a derelict fishing gear (DFG) is a critical threat to marine organisms. To explore the effect of DFG on sea turtle strandings, the DFG distribution was compared at two sites on Jeju Island (South Korea) with a contrasting number of strandings. Coastal areas in northern Jeju Island were surveyed during dives with scuba equipment, and the DFG from two sites, Gwideok-ri and Sinchang-ri was collected and compared in terms of quantity and size of the items.

First record of plastic debris ingestion by a fin whale (Balaenoptera physalus) in the sea off East Asia.

Marine pollution caused by plastic litter can threaten the survival and health of marine organisms. In 2019, a juvenile fin whale (Balaenoptera physalus, length: 13.02 m, weight 12,000 kg) was found dead floating on the sea near Jeju Island, Republic of Korea.