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As seagrasses are not available with commercial nursery stocks, the removal of a large amount of plant materials may damage donor populations. We evaluated the recovery of the eelgrass Zostera marina following the removal of entire plant patches (0.01–0.49 m2) at the edge and interior of an eelgrass bed in Rongcheng Bay, Shandong Peninsula, China, through a field experiment. We investigated the shoot density, morphology and growth of recovering plants following excavation. We found that the removal of entire small patches with excavation areas ≤0.25 m2 in the interior of the eelgrass bed was the most suitable strategy for harvesting donor plants of Z. marina. Small patch excavation (≤ 0.25 m2) was able to promote asexual reproduction in recovering plants, and their shoot density and morphology equaled or exceeded those of natural plants <7 months after harvesting. These results indicate that Z. marina plants have a strong capacity for resilience from physical disturbance through rhizome elongation in the harvested area. [ABSTRACT FROM AUTHOR]

Seagrass is an important foundational species in marine ecosystems that plays an important role in providing ecosystem services. However, seagrass distribution and suitable habitat have rapidly declined in recent decades because of climate change and human-mediated disturbances. To achieved better conservation and management of the seagrass Zostera marina , an important representative seagrass in northern China, studies must investigate how this species responds to climate change. Here, we used an ensemble species distribution model to forecast the potential distribution and future suitable habitat change for the eelgrass Z. marina in coastal areas of the Bohai Sea and Shandong Peninsula, China. Two future climate scenarios, RCP 4.5 and RCP 8.5, were considered, which represent stable and high levels of greenhouse gas emissions, respectively. The ensemble model accurately predicted the current Z. marina distribution and performed better than the single-algorithm methods of random forest, generalized boosting model and maximum entropy according to performance matrices (AUC and TSS). The distance to land (78.50 ± 3.51%) and the maximum sea surface temperature (11.90 ± 0.25%) were the most important variables determining the distribution of Z. marina , while the contributions of other variables, maximum sea surface current velocity (3.80 ± 0.33%), minimum surface salinity (2.15 ± 0.22%) and water depth (1.74 ± 0.24%) were relatively low. Under future climate scenarios, the suitable habitat of Z. marina was predicted to decrease by more than half by the 2050s, whereas under the pessimistic greenhouse gas emission scenario (RCP 8.5), suitable Z. marina habitat was predicted to decrease by nearly 80% by the end of this century. The loss of Z. marina seagrass beds will have important ecological effects on the marine ecosystem. Our results not only provide valuable information to assist in identifying potential Z. marina meadows, but also have important implications for guiding conservation and management of Z. marina in the northern coastal region of China. • The distribution and suitable habitat of Zostera marina was predicted under current conditions and future climate scenarios. • Ensemble model could accurately predict the present distribution of Zostera marina compare with single-algorithm models. • Climate change may lead to over 50% loss of the suitable habitat for Zostera marina in northern coastal areas of China. [ABSTRACT FROM AUTHOR]