Seasonal changes of planktonic polychaete larvae and chlorophyll a concentration in Onagawa Bay, northeastern Japan

Figures & data

Figure 1. Location of the sampling station in Onagawa Bay.

Figure 2. Seasonal changes of temperature (°C) and salinity (PSU) at the surface and near bottom of water column at St. 1 in Onagawa Bay during the period from 2007 to 2009.

Figure 3. Seasonal changes of GF/F-filtered chlorophyll a concentration in the water column at St. 1 in Onagawa Bay from 2007 to 2009. (a) Chlorophyll a concentration at 0, 5, and 15 m in the water column; (b) vertical profile of chlorophyll a concentration.

Figure 4. Seasonal change of size-fractionated chlorophyll a concentration at 0, 5, 10, 15, and 20 m depth in the water column.

Table I. Seasonal density dynamics of planktonic polychaete larvae in Onagawa Bay from 2007 to 2009. Each number shows the minimum and maximum densities (ind m⁻³) for each month, and total shows the total individual numbers counted (ind m⁻³) for each group over three years

Taxon	Jan.	Feb.	Mar.	Apr.	May	June	July	Aug.	Sep.	Oct.	Nov.	Dec.	Total
Polydora	12–6267	38–221	89–416	185–608	91–1477	5–339	28–43	54–62	0–49	25–214	6–242	31–126	12227
Pseudopolydora	–	–	–	0–6	24–39	121–3121	131–604	214–679	27–196	90–316	39–64	0–18	7329
Prionospio	–	–	–	–	–	–	0–57	20–447	8–65	13–70	0–11	–	796
Other Spionidae	6–565	28–80	15–221	74–180	31–405	23–1980	43–449	63–267	0–125	90–424	39–167	54–653	7329
Serpulidae	–	–	–	–	–	–	0–371	0–398	0–10	0–13	–	–	1291
Nephtyidae	–	0–3	0–4	0–9	–	–	0–100	5–227	0–28	3–16	0–5	0–3	461
Magelonidae	–	–	–	–	–	–	0–59	9–107	4–68	0–20	–	–	385
Polynoidae	0–9	–	–	–	–	–	0–12	0–54	0–19	7–64	0–63	0–80	372
Phyllodocidae	–	–	–	0–5	0–12	–	0–56	0–42	0–37	7–39	0–38	0–39	320
Capitellidae	0–51	0–16	0–11	–	0–13	0–22	–	0–14	–	0–4	0–10	0–54	225
Sylidae	–	–	–	–	0–12	–	–	–	–	–	0–195	–	212
Terebellidae	0–9	0–8	–	–	–	0–26	0–12	0–19	–	0–3	–	–	83
Nereididae	–	–	–	0–9	–	0–13	0–12	5–17	0–8	0–4	0–7	–	85
Arenicolidae	–	–	–	–	–	–	0–15	0–9	–	–	–	–	29
Chaetopteridae	–	0–3	–	0–9	–	–	–	0–5	–	–	–	–	17
Owenidae	–	0–3	–	0–6	–	–	0–4	–	–	0–3	–	–	16
Glyceridae	–	–	–	–	–	–	–	0–5	0–4	–	–	0–5	17
Dorvilleidae	–	–	–	–	–	0–7	0–4	–	–	–	–	–	11
Pectinariidae	–	–	–	–	–	–	0–4	–	–	0–4	–	–	8
Sabellidae	–	–	–	–	–	0–7	–	–	–	–	–	–	7
Lumbrineridae	–	–	–	–	–	–	–	–	–	–	0–4	–	4

Figure 5. Seasonal change of abundance of polychaete larvae at St. 1 in Onagawa Bay from 2007 to 2009. (a) Abundance of spionid polychaete larvae; (b) abundance of other polychaete larvae except Spionidae.

Figure 6. Seasonal change of abundance composition of spionid polychaete larvae at St. 1 in Onagawa Bay from 2007 to 2009.