3.1. Water Column Characteristics
According to the physical and chemical properties of water and quantitative characteristics of bacterioplankton, we delineated four zones relative to the proximity of the Khatanga River on the transect in the western Laptev Sea (Table 1). Stations 5627–5630 (73°4'N–74°2'N) were called Khatanga Bay (KHAB), characterized by lower salinity and higher temperature, DOC, abundance, mass of SPM (SPM), phytoplankton biomass, and abundance and production of bacterioplankton (Table 1). The stations on the shelf were combined into zones according to physical and chemical features. Stations 5631‒5632 (74°5'N–74°8'N) were called the Transition Zone (TZ) and were characterized by the influence of the Khatanga River, showing an average salinity below 25 psu, temperature higher than 1°C, and SPM concentrations higher than 10 mg m− 3. Stations 5591-2, 5590-2, and 5634 (75°4'N–77°6'N) are situated on the middle and outer parts of the western shelf (WS). They showed an average salinity higher than 30 psu, temperatures lower than 0°C, and SPM concentrations near 1 mg L− 1. Station 5635, located in the area of the continental slope (CS), was characterized by high salinity and the lowest SPM concentration. During the study period, the average phytoplankton biomass in the water column on the CS exceeded that in the TZ and on the WS (Table 1).
Table 1
Average and range of primary physical, chemical, and biological parameters on different transects of the study area. Depth: meter. Temp: temperature. S: salinity. DOC: dissolved organic carbon concentration. NPP: abundance of suspended particles 0.3–3.0 µm in size. NNMP: abundance of suspended particles > 3–210 µm in size. MNMP: weight of suspended particles > 3–210 µm in size. BPH: biomass of phytoplankton. NFB: abundance of free-living bacteria. NTB: total abundance of bacterioplankton: BTB: total biomass of bacterioplankton. PB: bacterial production
Parameters | Khatanga Bay (n = 7) | Transition Zone (n = 8) | Western Shelf (n = 12) | Continental Slope (n = 7) |
Depth | 21 (15‒27) | 31 (29–33) | 97 (45–183) | 860 |
Temp, °C | 3.0 (1.5–4.2) | 1.1 (− 1.3–2.6) | −0.5 (− 2.3–(− 1.6)) | − 0.5 (− 2.3–0.7) |
S, psu | 14.2 (3.5–26.0) | 24.4 (19–32) | 31.8 (22.5–34.6) | 34 (32.3–34.8) |
DOC*, gC m− 3 | 6.4 (4.3–8.7) | 4.5 (3.3–5.5) | 2.7 (1.9–4.3) | nd |
NPP, 105 particle mL− 1 | 4.5 (2.8–6.7) | 3.0 (1.3–6.8) | 1.8 (0.2–4.0) | 2.7 (1.8–3.7) |
NNMP, 103 particle mL− 1 | 134.0(19.3–282.7) | 9.0 (3.6–13.4) | 2.6 (0.1–11.2) | 0.4 (0.1–2.1) |
MNMP, mg m− 3 | 84.6 (9.1–205.6) | 11.9 (1.6–55.8) | 1.1 (0.01–4.40) | 0.02 (0.01–0.09) |
BPH**, mgC m− 3 | 19.4 (15.7–23.0) | 8.2 (3.7–12.7) | 1.5 (0.9–2.4) | 14.6 |
NFB, 105 cell mL− 1 | 7.5 (3.8–12.5) | 5.5 (3.4–11.6) | 2.3 (0.6–4.2) | 2.1 (0.8–2.7) |
NTB, 105 cell mL− 1 | 17.6 (13.4–23.1) | 8.0 (4.6–15.4) | 2.4 (0.8–4.4) | 2.1 (0.8–2.9) |
BTB, mgC m− 3 | 31.7 (27.9–37.7) | 15.9 (9.3–30.4) | 4.0 (1.3–9.5) | 3.5 (1.6–4.7) |
PB, 103 cell mL− 1 day− 1 | 561 (458–648) | 282 (201–437) | 53 (15–118) | 43 (16–65) |
PB, mgC m− 3 day− 1 | 10.3 (8.7–12.9) | 5.6 (4.2‒8.6) | 0.9 (0.2–2.6) | 0.7 (0.3–2.1) |
*, data from Drozdova et al. [33]; ** data from Sukhanova et al. [34]; nd, no data.
3.2. Abundance, Size and Morphological Composition of Free-Living Viruses
The abundance of free-living viruses (NVF) on the transect varied from 9.6 × 105 viruses mL− 1 to 86.3×105 viruses mL− 1 (Table 2). The average NVF increased in the direction from the Khatanga River estuary (20.1 ± 3.8 × 105 viruses mL− 1), to the TZ (43.8 ± 5.9 × 105 viruses mL− 1), to the WS (53.8 ± 6.1 × 105 viruses mL− 1), and to the CS (47.3 ± 10.2 × 103 viruses mL− 1). The ratio of abundance of free-living viruses to the abundance of free-living bacteria (VBRF) in coastal waters was lower by an order of magnitude than that in open waters (Table 2). In KHAB and the TZ, the VBRF values were higher than the values of the ratio of abundance of free-living viruses to the total abundance of bacteria (VBRT) by 2.1‒3.5 and 1.4‒1.6 times, respectively. In other regions, the difference between VBRF and VBRT was insignificant.
Table 2
Mean (min–max) abundance of free-living viruses (NVF, 105 viruses mL− 1), ratio of abundance of free-living viruses to abundance of free-living bacteria (VBRF), ratio of abundance of free-living viruses to total abundance of bacteria (VBRT) and capsid diameter of free-living viruses (DVF, nm)
Station | NVF | VBRF | VBRT | DVF |
Khatanga Bay |
5627 | 12.3 (10.5‒13.4) | 2.8 (1.6‒3.5) | 0.8 (0.7–0.8) | 50 (17–176) |
5630 | 26.0 (14.7‒40.5) | 2.7 (1.6–3.3) | 1.3 (0.6–1.8) | 43 (18‒170) |
Transition Zone |
5631 | 53.3 (37.0–78.3) | 8.3 (6.8–9.7) | 5.3 (4.5–5.9) | 45 (18–260) |
5632 | 34.2 (19.4–46.0) | 8.6 (3.6–13.5) | 6.2 (3.0–9.3) | 54 (18–260) |
Western Shelf |
5591-2 | 52.2 (36.6–70.0) | 34.3 (18.3–58.3) | 26.1 (18.0–35.6) | 46 (16–290) |
5590-2 | 53.2 (46.2–61.9) | 30.1 (15.2–39.7) | 28.5 (14.1–39.2) | 49 (18–250) |
5634 | 54.5 (9.6–86.3) | 25.4 (6.0–46.8) | 24.2 (5.9–46.8) | 52 (18–310) |
Continental Slope |
5635 | 47.3 (14.8–85.5) | 22.8 (9.6–36.0) | 21.8 (9.3–35.9) | 59 (18–300) |
Free-living viruses significantly negatively correlated with the abundance of suspended particles 0.3–210 µm in size (r = − 0.78; n = 34, p < 0.05) (Table S1). Since the abundance of suspended particles correlated positively with temperature, DOC, NH4, PO4, bacterial abundance, and production (Table S2), NVF also negatively correlated with these parameters (Table S1).
The capsid diameter of free-living viruses (DVF) varied from 16 to 310 nm (Table 2). The average capsid diameter varied between 43 and 59 nm per water sample, averaging 50 ± 2 nm for the 34 samples. The share of viruses with DVF less than 40 nm was higher in KHAB mixing waters, while the share of large viruses with DVF larger than 100 nm was higher in marine waters (Table 3).
Table 3
Share (% NVF) of viruses with capsid diameter of < 40, 40 − 60, > 60 − 100, > 100 − 150, > 150 − 200, and > 200 nm of abundance of free-living viruses
Region | % NVF* |
< 40 nm | 40‒60 nm | > 60‒100 nm | > 100‒150 nm | > 150‒200 nm | > 200 nm |
Khatanga Bay | 55.76 ± 2.67 | 22.68 ± 2.45 | 15.9 ± 2.25 | 4.52 ± 112 | 1.14 ± 0.60 | 0 |
Transition Zone | 43.66 ± 3.49 | 25.48 ± 1.61 | 23.05 ± 2.36 | 4.40 ± 1.02 | 2.30 ± 0.41 | 1.12 ± 0.42 |
Western Shelf | 40.85 ± 4.03 | 27.22 ± 1.89 | 23.62 ± 2.54 | 5.17 ± 1.07 | 1.79 ± 0.27 | 1.35 ± 0.17 |
Continental Slope | 28.85 ± 5.20 | 26.17 ± 4.00 | 29.32 ± 3.11 | 13.38 ± 4.71 | 1.42 ± 1.08 | 0.86 ± 0.57 |
*, mean ± standard error |
For the 14000 free-living viruses examined, four viral morphotypes were observed: myoviruses (morphotypes with contractile tails of various shape), siphoviruses (morphotypes with long noncontractile, often flexible tails), podoviruses (morphotypes with short tails), and nontailed viruses (Fig. 2).
In KHAB waters, podoviruses dominated (49–54% NVF), while nontailed viruses dominated (58‒65% NVF) in TZ waters (Fig. 3). In WS waters, the share of tailed and nontailed viruses was similar, while in CS watersm nontailed viruses predominated (60% NVF) (Fig. 3). The share of siphoviruses (1‒5% NVF) was lower than that of myoviruses, podoviruses, and nontailed viruses for all stations.
3.3. Abundance and Size of Viruses Attached to Bacterial Cells
The abundance of bacteria with viruses attached to their cells (NBV) varied from 0.2 to 2.9 × 105 cells mL− 1 (Fig. 2, Table 4). There were from one to 14 viral particles attached to the surface of a bacterial cell. From 1.3 ± 0.1 to 1.9 ± 0.3 viruses cell− 1 were on the surface of a bacterial cell on average per water sample. The share of free-living bacteria with attached viruses of the total abundance of free-living bacteria (NBV/NB, %) in Khatanga Bay was lower than in the other studied zones. The abundance of viruses attached to bacteria (NVB) varied between 0.3 and 4.9 ×105 viruses mL− 1. The average NVB values in the KHAB, TZ, WS, CS were, respectively, 1.6 ± 0.3, 1.9 ± 0.4, 0.9 ± 0.1, and 0.8 ± 0.1 ×105 viruses mL− 1. The capsid diameter of viruses attached to bacteria (DVB) varied from 20 to 150 nm. The average DVB per water sample varied between 44 and 74 nm, averaging 59 ± 3.3 nm for all stations (Table 4).
Table 4
Mean (min‒max) abundance of free-living bacteria with attached viruses (NBV, 105 cells mL− 1), share of free-living bacteria with attached viruses of total abundance of free-living bacteria (NBV/NB, %), abundance of viruses attached to free-living bacteria (NVB, 105 viruses mL− 1), and capsid diameter of viruses attached to bacteria (DVB)
Station | NBV | NBV/NB | NVB | DVB |
Khatanga Bay |
5627 | 0.6 (0.4–0.8) | 13 (10–20) | 0.9 (0.6–1.3) | 74 (25–132) |
5630 | 1.3 (0.7–1.9) | 14 (11–20) | 2.1 (1.1–3.6) | 60 (28‒120) |
Transition Zone |
5631 | 1.5 (1.0–2.9) | 22 (19–25) | 2.5 (1.6–4.9) | 64 (30–150) |
5632 | 0.8 (0.5–1.1) | 20 (16–22) | 1.1 (0.8–2.0) | 61 (47–83) |
Western Shelf |
5591-2 | 0.5 (0.2–0.8) | 24 (20–28) | 0.8 (0.3–1.4) | 44 (20–120) |
5590-2 | 0.5 (0.3–0.9) | 21 (20–21) | 0.7 (0.4–1.5) | 46 (20–80) |
5634 | 0.6 (0.2–0.9) | 27 (21–38) | 1.0 (0.4–1.6) | 67 (30–140) |
Continental Slope |
5635 | 0.5 (0.2–0.9) | 24 (17–32) | 0.8 (0.3–1.3) | 56 (20–150) |
3.4. Abundance and Size of Viruses Attached to Suspended Particles 0.3–3.0 µm in Size (Picosized Suspended Particles)
The abundance of suspended particles 0.3–3.0 µm in size or picosized suspended particles with attached viruses varied from 0.2 to 2.9 × 105 particles mL− 1 (Fig. 2, Table 5). There were from one to 34 viral particles attached to the surface of a single picosized suspended particle. From 1.3 to 7.8 viruses particle− 1 were on the surface of picosized suspended particles on average per water sample.
Table 5
Mean (min–max) abundance of suspended particles 0.3–3.0 µm in size with attached viruses (NPPV, 105 particles mL− 1), share of abundance of suspended particles 0.3–3.0 µm in size with attached viruses of total abundance of suspended particles 0.3–3.0 µm in size (NPPV/NPP, %), abundance of viruses attached to suspended particles 0.3–3.0 µm in size (NVPP, 105 viruses mL− 1), and capsid diameter of viruses attached to suspended particles 0.3–3.0 µm in size (DVPP, nm)
Station | NPPV | NPPV/NPP | NVPP | | DVPP |
| Khatanga Bay |
5627 | 1.4 (1.0–1.8) | 28 (22–33) | 5.1 (3.2–6.1) | | 62 (28–121) |
5630 | 1.4 (0.9–2.2) | 32 (31– 33) | 5.9 (1.9–10.2) | | 52 (33‒88) |
| Transition Zone |
5631 | 1.2 (0.7–2.7) | 33 (24–40) | 3.3 (1.5–7.6) | | 52 (20–161) |
5632 | 1.0 (0.4–1.5) | 38 (34–44) | 3.5 (0.6–5.9) | | 64 (20–210) |
| Western Shelf |
5591-2 | 1.0 (0.6–1.4) | 58 (39–75) | 2.8 (2.4–3.3) | | 52 (20–150) |
5590-2 | 0.9 (0.5–1.3) | 50 (44–54) | 1.6 (0.7–2.3) | | 53 (20–120) |
5634 | 0.9 (0.4–1.8) | 43 (40–48) | 2.2 (0.6–4.0) | | 67 (30–150) |
| Continental Slope |
5635 | 1.0 (0.2 − 0.9) | 38 (32–53) | 2.5 (1.7–3.6) | | 62 (20–160) |
The share of picosized suspended particles with attached viruses of the total abundance of picosized suspended particles in the KHAB was lower than in the other studied zones. The abundance of viruses attached to picosized suspended particles (NVPP) varied between 0.6 and 10.2 ×105 viruses mL− 1. The average NVPP values in the KHAB, TZ, WS, and CS were, respectively, 5.6 ± 1.0, 3.4 ± 0.8, 2.2 ± 0.3, 2.5 ± 0.3 × 105 viruses mL− 1. The capsid diameter of viruses attached to picosized particles (DVPP) fluctuated between 20 and 210 nm. The average DVPP per water sample were 52 − 67 nm, averaging 58 ± 2 nm for all stations (Table 5).
3.5. Abundance of Viruses Attached to Suspended Particles > 3–210 µm in Size (Nano- and Microsized Suspended Particles).
The minimum and maximum values of the abundance and mass of suspended particles of > 3–210 µm in size (or nano- and microsized suspended particles) with attached viruses differed by 6000 and 30 000 times (Table 6). In KHAB waters, suspended particles with a size between > 3 and 210 µm were present; in the TZ, only particles < 50 µm in size; in the WS and CS, particles < 20 µm in size. The shares of nano- and microsized suspended particles with attached viruses in the KHAB–TZ and WS‒CS accounted for 60‒68 and 70‒85% of the total abundance, respectively. The abundance of viruses attached to nano- and microsized suspended particles (NVNMP) varied between 0.01 ×105 and 15.0 ×105 viruses mL− 1. The average NVNMP values in the KHAB, TZ, WS, CS were10.4 ± 1.0; 5.8 ± 0.4; 0.5 ± 18; 0.02 ± 0.03 ×105 viruses mL− 1, respectively. The mean values of the ratio of particle-attached viruses to the abundance of particle-attached bacteria (NVNMP/ NBNMP) in the KHAB, TZ, WS, and CS were 1.1 ± 0.1, 3.3 ± 0.7, 4.6 ± 1.7, and 2.9 ± 1.0, respectively.
Table 6
Sizes of suspended particles (size, µm), mean (min-max) abundance (NNMPV, 103 particles mL− 1), and mass (MPB, gm− 3) of suspended particles with > 3‒210 µm in size with attached viruses, abundance of viruses attached to suspended particles > 3–210 in size (NVNMP, 105 viruses mL− 1), ratio of abundance of particle attached viruses to abundance of particle-attached bacteria (NVNMP/ NBNMP)
Station | Size | NNMPV | MNMPV | NVNMP |
Khatanga Bay |
5627 | > 3–210 | 121.2 (78.8–188.6) | 245.5 (175.2–377.1) | 12.6 (11.0–15.0) |
5630 | > 3–210 | 75.3 (12.1‒131.8) | 73.9 (7.4–179.3) | 8.8 (6.1–11.8) |
Transition Zone |
5631 | > 3–50 | 10.2 (7.2–12.3) | 18.0 (6.6–45.1) | 6.4 (5.5–7.1) |
5632 | > 3–50 | 4.5 (1.2–6.7) | 14.6 (0.1–55.6) | 5.3 (3.6–6.6) |
Western Shelf |
5591-2 | > 3–50 | 3.5 (0.6–9.0) | 2.0 (0.2–3.4) | 0.8 (0.1–1.9) |
5590-2 | > 3–20 | 3.0 (1.3–6.3) | 1.8 (0.4–4.4) | 0.8 (0.3–1.9) |
5634 | > 3–20 | 0.8 (0.4–1.4) | 0.1 (0.02–0.12) | 0.2 (0.1–0.3) |
Continental Slope |
5635 | > 3–20 | 0.08 (0.03–0.16) | 0.02 (0.01–0.09) | 0.02 (0.01–0.03) |
3.6. Total Abundance of Viruses
In the western Laptev Sea, virioplankton included free-living viruses (NVF), viruses attached to bacteria (NVB), viruses attached to picosized particles (NVPP), and viruses attached to nano- and microsized particles (NVNMP). As a result, the total abundance of virioplankton (NVT) fluctuated in the water column from 17.2 to 92.0 × 105 viruses mL− 1. The average NVT values in the KHAB, TZ, WS, and CS were 37.8 ± 3.7, 54.9 ± 6.3, 57.4 ± 6.3, and 50.6 ± 1.0 × 105 viruses mL− 1, respectively (Fig. 4). There was a strong inverse relationship between the abundance of free-living viruses and abundance of viruses attached to suspended particles: (r = − 0.72; n = 34, p < 0.05). NVT moderately negatively correlated with the abundance of suspended particles (Table S1).
The virioplankton structure at station 5627 differed from that at other stations by a higher share of viruses attached to suspended particles (57.1%) and a lower share of free-living viruses (39.8%) (Fig. 5). At stations 5590-2‒5635, the contribution of free-living viruses to the formation of NVT increased to 93‒94%. The share of viruses attached to bacteria did not exceed 5%.
3.7. Viral Infection and Virus-Mediated Mortality of Bacterial and Viral Production
The frequency of visibly infected free-living bacterial cells (FVICF) in the western Laptev Sea ranged from 0.5 to 2.8% of the abundance of free-living bacteria (NBF), averaging 1.2 ± 0.1% NBF. A negative strong correlation was observed between FVICF and the abundance of suspended particles 0. 3–3.0 µm in size (r = − 0.76; n = 34, p < 0.05), and a negative but weak correlation was observed between FVICF and the abundance of suspended particles > 3.0‒210 µm in size (r = − 0.27; n = 34, p < 0.05). At the same time, FVICF correlated positively with the abundance of free-living bacteria (r = 0.63; n = 34, p < 0.05) and free-living viruses (r = 0.59; n = 34, p < 0.05), bacterial production (r = 0.40; n = 25, p < 0.05). A positive moderate correlation was observed with temperature (r = 0.32; n = 34, p < 0.05) and DOC (r = 0.39; n = 34, p < 0.05). A negative moderate correlation was observed with NO2 + NO3 (r = − 0.50; n = 34, p < 0.05) and PO4 (r = − 0.55; n = 34, p < 0.05) (Table S1).
In the KHAB and TZ, the frequency of visibly infected bacterial cells in water with a large amount of SPM was determined not only for free-living bacteria (FVICF), but also for particle-attached bacteria (FVICP). In most samples taken in the KHAB and TZ (in 10 out of 15), the FVICP values were higher than those of FVICF (Fig. 6). The average FVICF values in the population of free-living bacteria (1.3 ± 0.1% NBF) were a little lower than FVICP in the population of particle-attached bacteria (1.6 ± 0.2% NBP).
FVIC calculated for the bacterial community (free-living and particle-attached bacteria) in the western Laptev Sea ranged from 0.5 to 3.2% NBT, averaging 1.3 ± 0.1% NBT (Table 7). The average FVIC values in the KHAB, TZ, WS, and CS were 1.3 ± 0.1, 1.7 ± 0.2, 1.2 ± 0.1, and 1.0 ± 0.2% NBT, respectively.
Table 7
Mean (min–max) frequency of visibly infected bacterial cells (FVIC, % NBT), frequency of infected bacterial cells (FIC, % NBT), virus-mediated bacterial mortality (VMB, % PB), mean (min–max) number of mature phages inside bacterial cells (BS, viruses cell− 1)
Station | FVIC | FIC | VMB | BS |
Khatanga Bay |
5627 | 1.2 (0.7–1.6) | 8.0 (4,9–10.8) | 9.0 (5.4–12.2) | 8 (5–12) |
5630 | 1.4 (1.3–1.4) | 9.0 (8.9–9.0) | 10.6 (10.4–10.6) | 9 (4–35) |
Transition Zone |
5631 | 1.9 (1.1‒3.2) | 12.5 (7.5–20.1) | 16.2 (8.6–29.6) | 11 (4–27) |
5632 | 1.4 (1.2–1.9) | 9.5 (8.2–12.5) | 11.4 (9.5–15.8) | 8 (4–35) |
Western Shelf |
5591-2 | 1.2 (0.8–1.4) | 7.8 (5.5–9.0) | 9.0 (6.1‒10.6) | 11 (4–23) |
5590-2 | 0.9 (0.8–1.0) | 6.4 (5.5–6.9) | 7.2 (6.1–7.8) | 15 (4–23) |
5634 | 1.4 (0.5–2.3) | 9.1 (3.5–14.9) | 11.2 (3.7–19.7) | 11 (4–34) |
Continental Slope |
5635 | 1.0 (0.5–1.8) | 6.8 (3.5–11.9) | 7.9 (3.7–14.9) | 11 (4–29) |
The FVIC, as well as FVICF, negatively correlated with the abundance of suspended particles 0.3–3.0 µm in size (r = − 0.68; n = 34, p < 0.05) and positively with the abundance of free-living bacteria (r = 0.67; n = 34, p < 0.05) and free-living viruses (r = 0.50; n = 34, p < 0.05), with total abundance of bacterioplankton (r = 0.51; n = 34, p < 0.05), with bacterial production (r = 0.57; n = 25, p < 0.05). A positive moderate correlation with temperature was observed (r = 0.40; n = 34, p < 0.05) and DOC (r = 0.48; n = 34, p < 0.05). A negative moderate correlation was observed with NO2 + NO3 (r = − 0.56; n = 34, p < 0.05) and PO4 (r = − 0.59; n = 34, p < 0.05) (Table S1).
Calculations based on the FVIC estimates showed that the share of virus-infected cells of NBT (FIC) varied from 3.5 to 20.1% of NBT (on average 8.6 ± 0.4% of NBT), and the viral-mediated mortality of bacteria (VMB) was 3.7‒29.6% (on average 10.3 ± 0.8%) of bacterial production. The number of phages in viral-infected bacterial cells (BS) fluctuated from 4 to 35 phages cell− 1, averaging 11 ± 1 phages cell− 1 (Table 7).
Bacterial mortality caused by viral lysis (VIM) varied widely (Table 8). The average VIM values in the KHAB and the CS differed by 25 times. Values of the production of viruses (PV) in the KHAB and TZ were higher compared to those in the WS and CS (Table 8). The turnover time of abundance of free-living viruses (TVF) increased in the direction from the river estuary to the open sea. Strong positive correlations were found between T°C and PV and between PB and PV: r = 0.62, n = 25, p < 0.05 and r = 0.84; n = 25, p < 0.05 respectively.
Table 8
Average and range of parameters of viral activity on different transects of western Laptev Sea. VIM: viral-induced mortality of the bacteria. PV: viral production. TVF: viral turnover time of abundance of free-living viruses.
Parameters | Khatanga Bay | Transition Zone | Western Shelf | Continental Slope |
VIM, 103 cell mL− 1 day− 1 | 54.4 (31.4‒67.4) | 35.0 (15.1‒87.8) | 4.6 (1.1‒12.5) | 2.1 (1.2‒2.6) |
VIM, mg C m− 3 day− 1 | 1.0 (0.7‒1.2) | 0.7 (0.3‒1.7) | 0.08 (0.01‒0.3) | 0.04 (0.02‒0.04) |
PV, 103 cell mL− 1 day− 1 | 448 (251‒674) | 320 (128‒878) | 57 (15‒113) | 30 (19‒53) |
TVF, day | 3.9 (2.4‒5.5) | 20.4 (8.9‒35.8) | 138 (57‒240) | 150 (78‒189) |