Information Times (Reporter C✘ heng Xiaozhen, Correspondent Li Shu) Recently, C∑≤hen Tianran, a researcher from the Coral Reef an ±©πd Environmental Recording G"Ω§≈roup of the Key Laboratory of Margin↔βal Sea and Ocean Geology, Chinese Academ↕λy of Sciences, and Professor Zhao Jianxin of the λ←∞University of Queensland, Australia, haφ ve made achievements in the study of coral ≠™☆reef development patte ®λrns. The latest progre€€$ss, relevant research results werε>₹e published in the "π±λJournal of General Environmental Sci'∏✔ence").
The dead staghorn and pontoic corals are sh↓ ocking; each U-Th peak corresponds to t← he death of a large number of coral£→$s that year. Photo courtesy of the corr≠¶espondent
Most of the nearshore coral reefs are showing ÷< σa rapid trend of degr₩α£adation
The earth has entered a new"↕ era, the "Anthrε opocene", which is §↓♥×characterized by "significant changes i✘™←n the earth system by human acti∞σ♠→vities". Accordi←< ng to reports, compared with the o✔¥&€ceanic coral reefs far away ₩₩δ from the mainland, in addition to the st$£ress of climate change, the ✔≈ near-shore coral reefs are also supe €π÷rimposed by the strong <↔interference of human act♠£ivities, and most of them sh↑±≠ ow a trend of rapid degradation, that is, they <¶σgradually transition to (or have become) λ<"marginal coral reefs&quoβ★t; ".
It is understood that the Northwest Pac Ωific (including Southea•γ ∏st Asia and the northern part of the South <∏→♣my country Sea) and the Atlantic Caribbean ∑↓∏Sea are two typical regio♥εns in the world, but the research ↓σ<on coral reefs in the Sout ®→h China Sea is far lower t©<δhan that in the Caribbean Sea. Th∏"♣←is is mainly due to the lack of long-ter'∏m observations and accumulation of≈ historical data and data, which r ©→©estricts a comprehensive and in-depth understand₩∞ing of the degradation and developmeπ÷nt history of coral ¶∑∞✘reefs in the South Chin∏★πa Sea and their "causes".
Mass coral die-off occur∏ red as early as around 1950
Using high-precision Uα↓-Th radioisotope dating technology, the re≤÷☆σsearchers measured about 100 ma<≤↕ssive and branched coral samples from Weizh§€ou Island in the northern South ∏£₹'China Sea, and analyzed the γdeath age and species, revealing the evolution o≤¶&÷f coral reefs in the pσast 100 years. history. The study found tha©→'t the massive death of corals and the degr∞₩™©adation of coral reefs actually occurred as earl π→≈y as around 1950, far earlier than the recor∑≠ds of modern observations, and coincideγ♥d with the "Great Acceleration of the Anthr <"←opocene".
The study also revealed that th∑πσ♣e frequency and extent of cor©β☆al mortality in the nort&☆hern South China Sea has gradu♣λally increased since 1980. ™₩£↓The main periods of staγ≥¥≥ghorn coral death and community >↕&collapse occurred in 1960, 1984, and 1998, ≥α≠with trends such as sharp reductions in co'®♣>ral cover and changes in dominant spe→©€✘cies.
Based on the distributi₩÷on curve of coral death y¥ ∏↑ears, the researchers corr✔∏€elated peak coral mortality with speciγ©εfic extreme climate € αevents (such as winteσ★r cold events) and human ac≤×tivities (such as fishing, mariculture, agricul←€tural reclamation, tourism♥™ development, infrastructure Construc±✘tion) one by one, and found the &qu&∏ot;cause": the ←π¥destruction of human ac' tivities in this area far exceeds the₽≥ impact of climate change.
In addition, the study also foα♦♠und that the ancient coral re ₩™ef deposits on land (uplifted) were mai✘£nly composed of staghorn ✘∏corals, and their ages were distribut®π ≥ed since the late Holoc ∞←ene, indicating that the nor& ≥ thern fringing reef area of the South Chγ× ↕ina Sea is likely to be dominated by stagα Ω₽horn corals for thousands of₩ years. In just 50 years after the "G♥✔™'reat Acceleration", ∏ human activities have completely chan§≤ged the developmental pattern that coral reefs↓→ have maintained for thousands of year§§₹s, thereby gradually ™≥€"marginalizing".
Based on the results of th₽€✘<e study, the researchers↓™ made a scientific answer to the "∏✔♦;Question of Coral Reef≥ $↕s in the South China Sea" and gave sc≤✘ ientific advice on how to effectively ♠≠♦protect and restore coral reefs. It ✘£§is reported that this research was funded≈β by the National Natural Science Foundation of C≈♦hina, the Southern Ocean Science and Engi₹☆neering Guangdong Laboratory (Guangzhou) ¥&∑team project and the Guangdong Pro★±vincial Natural Science Foundation.
Source: Information Times