highly significantp < 0.01
3 a–d) showed that OM in sediment before the LWLO had a highly significant positive correlation with TN (r = 0.699, p < 0.01) and a significant positive correlation with TP (r = 0.567, p < 0.05), while OM in sediment during the LWLO had a highly significant positive correlation with TN (r = 0.892, p < 0.01) and TP (r = 0.766, p < 0.01).