Seasonal Variations of Marine Environment and Primary Production in the Taiwan Strait

Abstract

The first data set of seasonal marine environment and euphotic zone integrated primary production (IP) variations in the Taiwan Strait was reported. The measured annual IP was 123 ± 86 gC m −2 year −1 (338 ± 235 mgC m −2 day −1), and its seasonal variations can be described with a left-skewed normal distribution curve. The average seasonal IP values from the highest to the lowest were summer (664 ± 270 mgC m −2 day −1), autumn (350 ± 118 mgC m −2 day −1), spring (202 ± 110 mgC m −2 day −1), and winter (137 ± 68 mgC m −2 day −1). The lowest IP was during the nutrient-rich winter because it had a short insolation duration, low incident photosynthetic active radiation (PAR) and low light transmission (shallow euphotic zone depth) due to strong vertical mixing. In contrast to the winter, the highest IP was during the nutrient-depleted summer, which had a long insolation duration, high incident PAR and high light transmission (deeper euphotic zone depth). In addition, the heterotrophic nutrients from upwelling in the south might also support the highest IP in summer. As three primary water masses exist in the Taiwan Strait and three of them have different characteristics, different mixing ratios of water masses may cause different chemical and hydrographic conditions, which leads to different levels of Chl a concentrations and primary production. It is worth to mention that offshore wind farm (OWF) construction in the Changyun Rise (CYR) of the Taiwan Strait is ongoing. As primary production is the foundation for a marine ecosystem and supports the food web and fish stock, the results of this research can not only be used as the baseline for evaluating the OWF impact on the marine ecosystem but also be used for assessing their influence on fishery resources.

Contrasting Effects of Regional and Local Climate on the Interannual Variability and Phenology of the Scyphozoan, Aurelia coerulea and Nemopilema nomurai in the Korean Peninsula

“…These climate phenomena mold regional weather patterns at interannual and decadal scales, thereby affecting temporal changes of marine taxa and food web dynamics. The East Asian marginal seas are characterized by high nutrient load promoted by hydrographic features that boosts large primary and secondary production, thus favoring environmental conditions for fishery [5,6]. Indeed, this region is one of the world's most productive fisheries grounds [5].…”

Shifts in the Assemblage of Summer Mesopelagic Fish Larvae in the Gaoping Waters of Southwestern Taiwan: A Comparison between El Niño Events and Regular Years

“…The composition of phytoplankton community can be changed by the entrained nutrients. Furthermore, variation in the intensity of seasonal monsoon can also alter the timing of the phytoplankton bloom in the TS [65]. Taken together, these factors all contribute to the survival and growth of zooplankton and further influence the distribution and occurrence of mesopelagic fish larvae in the Gaoping waters.…”

Cumulative impacts of wind farms on the North Sea ecosystem

“…A strong increase of primary production was found up to 50 km outside the OWF area (Slavik et al, 2019). Tseng et al (2020) measured average primary production and its seasonal variations in the Taiwan…”

“…As shown in Figure 17, offshore wind farms may affect the ecological carrying capacity of the North Sea, both during the construction phase as well as during production phase. Activities during the construction phase are likely to increase the natural background levels of suspended particulate matter (SPM) in the water column (Tseng et al, 2020). Increased suspended particles may decrease light penetration and therewith decrease primary production (Tseng et al, 2020 and references therein;Dannheim et al, 2020).…”