The distribution of large floating seagrass (Zostera marina) aggregations in northern temperate zones of Bohai Bay in the Bohai Sea, China

Abstract

Seagrass meadows (Zostera marina) are important coastal ecosystems with high levels of productivity and biodiversity. They often have high biomass turnover and are susceptible to dislodgment, leading to export of biomass from seagrass beds. In September 2016, two cruises covering a total area of 52 km x 15 km (38°57'1.14"–39° 0'41.28" N, 118°45'23.22"–118°47'6.96" E) found floating Z. marina aggregations along 13 km of the transect in the northernmost area of Bohai Bay, in the Bohai Sea, China. This floating seagrass was 6.3–13.4 km northeast (offshore) of the Caofeidian seagrass bed, which is a large (10 km2) seagrass bed discovered in 2015 in the Bohai Sea, China. The modal length of floating intact shoots (from meristem to longest leaf tip) matched samples from the Caofeidian seagrass bed. The dominant individuals lengths were 40–50 cm, with less than 5% of the total number of individuals found in larger size categories (80–90 and 90–100 cm). We concluded that they originated from the nearby Caofeidian seagrass meadows.

Coastal Ecological Connectivity between Seagrass Bed and Marine Ranching 30 km Apart: A Case STUDY of Apostichopus japonicus Feeding on Seagrass Debris in the Bohai Sea, China

“…These leaves are transported by winds and currents over approximately 30 km to reach the marine ranching area in Xiangyun Bay. The verified presence of floating seagrass northeast of the bed strongly supports the notion that seagrass is being transported towards the marine ranching area [35]. Consequently, some of these leaves settle within the ranching zone.…”

“…The national seagrass resource surveys conducted from 2015 to 2020 have revealed the presence of only one eelgrass bed in Tangshan's coastal waters, which happens to be the largest in China. Strong evidence suggests that the floating seagrass consumed by A. japonicus in the marine ranching originates exclusively from this particular bed [34,35]. Due to its high primary productivity [53], seagrass meadows continuously shed leaves that eventually float to the sea surface [54] and are subsequently transported away by winds and currents [11,55].…”

Chicoric Acid: Natural Occurrence, Chemical Synthesis, Biosynthesis, and Their Bioactive Effects

“…Some studies have shown that the content of chicoric acid varies in different parts of the plant (Grignon-Dubois and Rezzonico, 2013). Zostera marina, the most widespread seagrass species of Potamogetonaceae throughout the temperate northern hemisphere (Min et al, 2019), is the largest seagrass meadow in the Bohai Sea and Yellow Sea areas in China. Although chicoric acid has been detected in the leaves of Z. marina, the data are incomplete (Pilavtepe et al, 2012).…”