While marine kelp forests have provided valuable ecosystem services for millennia, the global ecological and economic value of those services is largely unresolved. Kelp forests are diminishing in many regions worldwide, and efforts to manage these ecosystems are hindered without accurate estimates of the value of the services that kelp forests provide to human societies. Here, we present a global estimate of the ecological and economic potential of three key ecosystem services - fisheries production, nutrient cycling, and carbon removal provided by six major forest forming kelp genera (Ecklonia, Laminaria, Lessonia, Macrocystis, Nereocystis, and Saccharina). Each of these genera creates a potential value of between $64,400 and $147,100/hectare each year. Collectively, they generate between $465 and $562 billion/year worldwide, with an average of $500 billion. These values are primarily driven by fisheries production (mean $29,900, 904 Kg/Ha/year) and nitrogen removal ($73,800, 657 Kg N/Ha/year), though kelp forests are also estimated to sequester 4.91 megatons of carbon from the atmosphere/year highlighting their potential as blue carbon systems for climate change mitigation. These findings highlight the ecological and economic value of kelp forests to society and will facilitate better informed marine management and conservation decisions.

Hyperpigmentation diseases of the skin require topical treatment with depigmenting agents. We investigated the hypopigmented mechanisms of sargahydroquinoic acid (SHQA) in alpha-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 cells. SHQA reduced cellular tyrosinase (TYR) activity and melanin content in a concentration-dependent manner and attenuated the expression of TYR and tyrosinase-related protein 1 (TRP1), along with their transcriptional regulator, microphthalmia-associated transcription factor (MITF). SHQA also suppressed α-MSH-induced cellular production of cyclic adenosine monophosphate (cAMP), which inhibited protein kinase A (PKA)-dependent cAMP-responsive element-binding protein (CREB) activation. Docking simulation data showed a potential binding affinity of SHQA to the regulatory subunit RIIβ of PKA, which may also adversely affect PKA and CREB activation. Moreover, SHQA activated ERK1/2 signaling in B16F10 cells, stimulating the proteasomal degradation of MITF. These data suggest that SHQA ameliorated hyperpigmentation in α-MSH-stimulated B16F10 cells by downregulating MITF via PKA inactivation and ERK1/2 phosphorylation, indicating that SHQA is a potent therapeutic agent against skin hyperpigmentation disorders.

This study conducted a community investigation via scuba-diving excursions into the subtidal regions of seven sea areas on the eastern coasts and three sea areas on the southern coasts, from October to December 2017, to determine the characteristics of seaweed communities and the current status of barren ground in natural seaweed beds in Korea. The results showed that species composition and average biomass in the sea area were 5–48 species and an average of 114.42 g/m² (0.29–273.60 g/m²) in the eastern coasts, where red algae—an annual opportunity species—were dominant, and 21–48 species and an average of 1056.84 g/m² (53.03–2683.02 g/m²) in the southern coasts, where perennial large brown algae were dominant. Using Orfanidis’ EEI-c model, evaluations of the community states showed they varied significantly depending on the inclusion of melobesidean algae, and this model was determined to be inappropriate for direct application in sea areas with a low coverage of all macroalgae. A comprehensive review of the seaweed community characteristics of seaweed beds, the marine environment, the coverage of melobesidean algae, and the analysis results regarding the density of grazers showed that a decrease in the seaweed community, according to the barren ground phenomenon, was more severe in the eastern than southern coasts. Furthermore, there were also significant differences in seaweed community characteristics according to sea area and barren ground. Therefore, suitable countermeasures corresponding to the characteristics of each sea area are necessary; for example, the creation of growth substrates for the colonization of macroalgae in Deoksin and Saido Is., the transplantation of large brown algae in Gangyang and Daedurado Is., action plans for marine forest monitoring in Geomundo Is., and an improvement in substrates in Yeongjin, Mangsang, Daejin, Chogok, and Geundeok are possible countermeasures.

The common squid Todarodes pacificus is a dominant species within epipelagic communities and an important commercial species in the South and East seas of Korea and in the East China Sea. In this study, to examine the dietary composition, trophic position, and ontogenetic dietary shifts of the common squid, we analyzed stomach contents and stable isotope values (δ¹³C and δ¹⁵N) in muscle tissue across different body sizes (mantle length, ML) and seasons (winter, spring, and summer 2021) in the South Sea of Korea. Regardless of the season, the diet of the common squid predominantly comprised Pisces (37.9–94.0%) and Cephalopoda (6.0–61.0%). However, in the smallest individuals (ML < 10 cm), the stomach contents in August primarily comprised Crustacea (95.5%), thereby indicating a seasonal difference in dietary composition and ontogenetic dietary shifts only during summer. Similarly, our isotope results revealed seasonal isotopic variation among sampling periods and significant positive correlations between ML and both δ¹³C and δ¹⁵N values during the summer. These results reveal a seasonal variability in major diet components among the common squid of different size classes and that their feeding strategies are probably adjusted in response to the temporal availability of prey. Collectively, the findings of this study enhance our understanding of the feeding ecology of T. pacificus and thereby provide valuable information that will contribute to the ecological fishery management of this commercially important species.