the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 02 Feb 2024
Year-long benthic measurements of environmental conditions indicate high sponge biomass is related to strong bottom currents over the Northern Labrador shelf
Abstract. Deep-sea sponge grounds are distributed globally and are considered hotspots of biological diversity and biogeochemical cycling. To date, little is known about the environmental constraints that control where deep-sea sponge grounds occur and what conditions allow high sponge biomass to develop in the deep sea. Here, we characterize oceanographic conditions at two contrasting high- and low-sponge-biomass sites off the northern Labrador Shelf in Canadian waters. Unique data for the region were collected by year-long benthic lander deployments equipped with current meters, turbidity and chlorophyll-a sensors, and sediment traps. Additionally, the regional oceanography was described by analysing vertical conductivity/salinity-temperature-depth (CTD) and Argo float profiles for the Northern Labrador Shelf from 2005 to 2022, including those from the CTD casts taken at the benthic lander stations. Benthic fauna stable isotopes were analysed to identify potential food sources. Our results revealed strong (0.26 ± 0.14 m s-1; mean ± SD) semidiurnal tidal currents at the high-sponge-biomass site, but twofold weaker currents (0.14 ± 0.08 m s-1; mean ± SD) at the low-sponge-biomass site. These tidal currents cause periodic temperature fluctuations, sediment resuspension, intense vertical flows across the slope, which during spring, contribute to transport of organic material to the seafloor during a diurnal tidal cycle. Periodic fluctuations in bottom water temperature confirm the amplified transport across the shelf break at the high-sponge-biomass site. The high-sponge-biomass area is situated where the Hudson Strait Ouflow, the Irminger Current, and the West Greenland Current converge, which could lead to downwelling. Bottom silicate concentrations were increased at the high-biomass sponge ground due to advection of silicate-rich bottom water from Baffin Bay. Finally, the arrival of chlorophyll-a rich material in spring at both the low- and high-sponge-biomass sites demonstrated tight benthic-pelagic coupling prior to the onset of stratification. Mass fluxes of trapped material were higher and consisted of less degraded material at the high-sponge-biomass site. Stable isotope signatures indicated that soft corals (Primnoa resedaeformis) fed on suspended particulate organic matter, while massive sponges (Geodia spp.) likely utilized additional food sources. Our results imply that benthic fauna at the high-sponge-biomass site benefit from strong tidal currents, which increases food supply, and favourable regional ocean currents that increase nutrient concentration in bottom waters.
Status: final response (author comments only)
-
RC1: 'Comment on egusphere-2024-245', Ulrike Hanz, 16 Feb 2024
This study presents a long-term time series of environmental conditions within a deep-sea sponge ground. It shows that the food delivery is tightly coupled to the hydrodynamic regime, which defines the occurrence of sponge grounds. I enjoyed reading the manuscript since the study was nicely set-up and many factors that are important for sponge growth were considered. This study will help to entangle the question why sponge grounds establish in certain areas in the deep sea and presents new insight into the hydrodynamics of the seafloor. Year-long measurements of environmental conditions on the seafloor in the deep sea are sparse but can additionally be used to improve hydrodynamical models and even help to assess future changes caused by a changing climate.
There are some major points to consider. This manuscript and many of the figures are in parts already published as a deliverable from the ATLAS project (Wolff et al. 2020). Especially Figure 12, 13, S5, S6, S11 are completely or partly copied from the deliverable. These should be removed from this manuscript and should just be referenced if presented in the same context. I would suggest removing the isotope and respiration part of this manuscript, since there is no new data presented in this manuscript compared to the deliverable from Wolff et al.. Especially the part of carbon utilization assessment by the trawl and ROV transect (L708 ff) is unnecessary because there is no explanation of the methods explained or data shown, which removes a lot of credibility for the rest of the manuscript. The time-series of environmental conditions is anyways the focus of this study, which was (to my knowledge) not presented before. I would have liked if the author would put a bit more effort on the hydrodynamic of this region, including potential occurrence of internal waves, which are important for deep-sea communities in other areas. There is a relatively extensive description of the slope angle which should make a calculation of internal waves (or other hydrodynamic phenomena) possible. Some important data/figures were missing in my opinion: A table of the tidal constituents, the complete ADCP data set, the actual CTD transects or ice cover data (except in the supplements).
The abbreviation of LSB and HSB is used wrongly throughout the complete manuscript, which is hindering the flow of reading. LSB/HSB = “Low/High sponge biomass” (or is it “Low/High sponge biomass site”?) but was almost in every sentence used as “the low/high sponge biomass site”. Please use a better abbreviation and check every occurrence if it makes sense.
In general, there are many mistakes that should not appear in a submitted manuscript. For example, figure 1A is missing the complete description (probably wrong figure added?) and some references to figures are wrong.
Specific comments:
L2-3 The title should be reconsidered. The strong bottom currents are not the only important factor for the sponge ground in this manuscript but also the nutrient and food availability. That all is excluded with this title. All other than the benthic measurements are also excluded with this title (CTD and ARGO float are not benthic).
L38 Please remove “In Canadian waters”. The Labrador Shelf is already a unique area, and “Canadian waters” makes it sound political. Is your study region still in Canadas Exclusive Economic Zone?
L40 The sensor most likely measures fluorescence and not chlorophyll-a. The lander is equipped with one sediment trap, not multiple.
L41 Check the spaces, looks like there is too much space between some words (whole paragraph).
L42 I am confused about the ARGO floats. Were they deployed for this study? Where is the explanation? If not, why is there such a big focus on these floats? Presenting the data so extensively is not necessary and gives no additional information since the general flow pattern are known already.
L44 It seems like the study was not designed to identify potential food sources, since no food source except SPM was considered. Bacteria, dissolved OM and zooplankton are missing for example.
L47ff It was never really shown that tidal currents cause these things. Where are the correlations?
L51 How could this lead to downwelling?
L53 It's not clear for the reader of the abstract why silicate is important.
L58…compared to the low-sponge-biomass site.
L65-77 The line of thoughts is a bit confusing.
L75 Not limited to commercially important fish (also see Brodnicke et al. 2023)
L79 Maybe also mention deep-sea mining (Wurz et al. 2021).
L84 Maybe also mention reduced variation due to trawling (Morrison et al. 2020).
L102 Food availability was explained in the previous sentence. Gamete dispersal is also connected to currents (maybe connect the sentences).
L123 remove “any”
L126 I would be a bit careful with extending this too much. The Canadians have very good environmental datasets of their areas.
L136ff Please mark these areas on the map (with their name) otherwise it is impossible to follow.
Figure 1 There are no general circulation patterns marked in the map. Make the map bigger and add currents and names.
L154 remove “:”
L157 Rock boulders are no animal. It doesn’t make sense to list them in the same sentence with the fauna. The sediment plays a critical role for the occurrence for sponges and should be explained further. Please check the description of the sediment. It is not coherent within the manuscript.
L158 It is mentioned later (L613f) that at the LSB site consists of soft, muddy sediment. Figure 2 C&D also shows the opposite.
L163 You do not see the slope on the pictures.
Figure 2 Here you define HSB again as “high-sponge-biomass” without the “the” or “site”. Do not abbreviate words you don’t use further (DFO or CSSF). Pictures are difficult to compare because one is vertically downward with a drop camera and the other one more horizontally. Picture C and D could be the same area when you would take a vertical downward picture for example in the right corner of picture A. Maybe try to find other pictures from the same camera system. What distance are the lasers?
L184 “MHz” (make a capital M). Maybe state which particle size classes are observed with a 2 MHz ADCP. These settings will only detect really small particles.
L185 FLNTU abbreviation is not explained. Sensor measures fluorescence not directly Chlorophyll-a.
L186 I do not understand. The ADCP does not measure a 3D velocity field.
L188 Are you sure about altitude?
L190 Where is the complete data? There is no plot of the ADCP data. Are you sure the first bin is okay? Normally you have to discard (at least) the first two bins (~2-3m distance) since the lander is an obstacle in the flow field and it is highly influencing the (close) currents around it which influences the measurements.
L192 Later you state that data was transformed using the program MATLAB. Please clarify.
L192 Is the FLNTU not one sensor?
L193 The sediment trap is one device.
L195 Remove second dot.
L195 What’s the end of the collection? Did the last bottle last for the complete cycle? Was the last bottle closed before the lander was retrieved? If it is pulled through the water column while being open, data is not useable.
L204 Where are the plots of the CTD transects? Was there no sensor for turbidity? It would be interesting if turbidity around the high sponge biomass area is increased.
L214 You probably measured SPM and not sPOM. Where is the data?
L217 Cote et al. 2019 is not accessible (internet page with pdf is not existing anymore). Please give another reference (or a way to access it -DOI?)
L219 Explain why two different methods.
L240 POM or SPM?
L244 Please be more specific about the isotopic measurements. How reliable were the measurements? This data was already published before. Consider removing this part.
L245 Were these particles and swimmer also analyzed?
L270 Where is the data?
L271 Were specific parts of the fauna sampled or only whole animals?
L276 Was this the same as for the water column samples?
L277 What is this standard?
L280 see L192
L281 Why different programs? And which packages?
L286 What is the reason for a temporary shift? Did the lander move back again? That doesn’t make a lot of sense in my opinion. Where is the pitch and roll data?
L289 Explain NTU. Turbidity in NTU is not a concentration.
L293ff Which time-lag and how was the time leg assessed? Where is the outcome of these tests?
L297f First it was stated that unfiltered data was used and then it was stated that data was filtered before. What is right?
L300 Before it was stated that all analyses were performed in R. Please show the results of the harmonic analysis.
L303 Ice data not shown. Please add to supplements.
L312 remove “yet”. If significant show statistics.
L308ff It would be much nicer to show the transects.
L316 Sentence is more discussion.
L324 It makes no sense to give a range for a mixture of nutrients. The thermocline is not in the Figure.
L328 Remove “to a lesser degree” or give a more specific indication.
L334- 338 This seems weird here. It is not your results.
Figure 3 In A: Why pressure and not depth? All other graphs have depth as an y axis. In general, use the same units (Temperature or potential temperature/ salinity (PSU) or practical salinity). Both graphs have the same legend, combine and make uniform. Explain grey lines in figure C.
Figure 4 X-axis description is cut off. Make uniform capital or not (e.g. “Depth (m)” and not “depth(m)”). Maybe combine the legend for region. Its rather confusing. In general: Why not show the data as a transect from west to east?
Figure 5 A: Is this really important to show? I think the general currents could be shown in Figure 1. This figure is overloaded with data that is not further used and has some explanation issues. From which depths are the currents? The yellow arrows are not visible. And it is not clear what the difference with the blue arrows is (StE not explained). The dots are above the arrows, which makes it hard to see, which currents are at these positions.
B: I don’t really understand why this data is important to show. On the ARGO float locations from Figure S3 it seems that the ARGO float “HSB” is covering both stations and “LSB” is south of both stations. Make the y axis the same, so it is better comparable.
L361 Northward velocity was directed southward sounds wrong; I would describe it in a different way.
L363 is upward possible? Where is the water coming from?
L365 What is meant with bottom currents? Horizontal currents or the separate velocities? If not, horizontal currents please calculate them.
L367 Remove “signal” and talk about pressure (or water depth).
L371 Give table with tidal analysis.
L395 Why not recalculate the ABS to decibel sound pressure level to make it comparable to other data? Please show the complete data set of all bins (at least in supplements).
L400 Which turbidity? From ADCP or FLNTU?
L405 Reference to Figure S7 is wrong.
Figure F8: cut off the period when the lander was lifted, then you would very likely remove the peak in fluorescence and turbidity.
L412 Please give the complete correlation, not only r2 and show the correlation plot.
L413 ABS was explained before à ABS is also a measure for turbidity. It's confusing if ABS and turbidity are used but describing data from different devices. In general, I would not talk about “signal” but rather what the signal stands for. Every sensor gives just a “signal”. In L420 another “signal” (in the data) is mentioned. Very confusing.
L417 Show and give complete correlations.
L421 Figure S9 does not show ice cover. If S10 is meant I still don’t see how the ice cover is influencing Chl-a. Why is the data for this paragraph only showed in the supplements?
Table 1: What statistics are shown? It seems like these are just mean values and their SD. HSB and LSB are again defined differently than before. Bottom current speed= horizontal current speed? ABS is also a measure for turbidity. How is along and across slope velocity calculated?
Figure 7 I do not think that this is the best way of showing the data. First of all, progressive vector plots might be useful to show transport for short time periods, but after more than some days these plots are invalid. At every new position a parcel of water experiences different forcing, that are not comparable to the initial position. Especially factors like temperature are very different at each position because of the general water mass distributions. I do not believe that you can extract any useful information from this plot. Additionally, it was shown before that tidal currents are influencing temperature which are not even included in this figure. Figure 7C&D are on the other hand a nice way of showing the current direction distribution, whereas it is not clear why not the same way of visualization like for example current speed was used (maybe not useful).
Figure 8 C is difficult to see the difference between temperature, ABS and Chl-a. I would suggest different colors and to move the legend to the right side.
Figure 9 This is in principle a more acceptable that Figure 7. Turbidity (counts) for example is depending on the current speed which is not at all visible in this graph. Turbidity is not differing on small scale spatial patterns as it seems in this plot. The same for temperature. Temperature depends on the current direction of the water mass with a certain temperature. This graph suggests that temperature varies on a small spatial scale. Data needs to be shown differently.
Figure 10 Nice way of showing the data. ABS should also be called turbidity or any other coherent way (acoustic vs. optical backscatter). Chl-a needs to be with a capital C. The two different turbidity signals should be used to describe the particle sizes of the SPM (peaks in spring= bigger particles because not seen in the ADCP data). The data of the last days before the retrieval of the lander can probably be cut off, since it is likely showing the time period when the lander was lifted, or other bottom touching activities were nearby.
Figure 11 This makes Figure 9 obsolete. Much nicer way of showing the data. Same comments for the y axis description like before. Again, comparing the turbidity sensors here would help with the particle description à Fine sediments are dependent on tidal currents and are peaking with a high horizontal velocity when currents are in a certain direction (I assume when currents are coming from the shelf, current direction is missing here). A correlation matrix would help here as well.
L457-495 Remove everything that is redundant from the already published data (Wolff et al. 2020). Or mark it better as a repetition if needed to be included.
L486 “indicated a lower trophic level..” is for the discussion.
Figure 12 Most of this figure was published already.
Figure 13 This is not a bi-plot (includes sample data and variable data). The plot was already published before and is therefore redundant. Other food sources are missing (zooplankton, dissolved food).
L499 remove “more specifically.”
L521 “Our ARGO float profiles”. The ARGO data is not from this study, this is misleading.
L529 How was this calculated?
L532 Why is the water temperature explaining salinity?
L540 What is in-situ remineralization supposed to be? Remineralization in the Baffin Bay? Why is there more organic matter in the deep-water that is demineralized? Is it not primary production or terrestrial OM that is demineralized? Normally deep water has higher nutrients but not higher OM.
L567 The tidal amplitude? Or tidally driven horizontal currents?
L568 This is highly dependent on the sponge species. Are these the same sponges?
L578 Why is the ARGO float data important here?
L584 I would expect current direction to have an effect but not tidal currents.
L587ff Currents at the shelf break are likely very different than on the shelf and this is likely not a valid argument even though the time frame would maybe allow assumptions like this.
L606 Logically not completely right. Higher resuspension is clogging the sponge due to more particles in the water column. The particles are also retained within the sponge and are not removed from currents.
An important point is also that resuspension is delivering food since bacteria and organic substances are binding to particles, which will be eaten. Higher turbidity is associated to higher amounts of bacteria.
L614 contrary to what was mentioned before and also pictures show something else.
L616 Check your data. Is there a time lag between high currents and high turbidity? Then SPM is likely coming from somewhere else. Otherwise, OM might be collected between the sponge (and other fauna), like mentioned in the introduction.
L618 I don’t agree that it prevents smothering.
L619 It is known that OM/bacteria are binding to particles and can act as a food source. Third? What is first and second?
L635 repetition.
L638 Show prim. production.
L650 Which export? I assume from the Hudson Strait. Why is the export tidal?
L677 Why would that have an influence? They produce offspring when they have enough energy but that can happen to any time of the year.
L689 Was not Chlorophyll-a measured here and not fluorescence?
L706 It seems that a more important factor is the horizontal distance to the food source from the Hudson Bay or Baffin Bay.
L708-730 This paragraph is not okay in this way. There is no explanation about the estimate of the sponge biomass by the ROV or trawl method, which is a number that is not easy to obtain. Sponge biomass of a trawl cannot be referenced with personal communication. The image analysis was already published in an earlier report and also discussed there. The paragraph is based on a comparison of these results and the data from personal communication and there are no results concerning this paragraph in this manuscript. Therefore, this paragraph should be removed. The respiration potential can be discussed in one sentence when needed but it should be clear, how estimates are made or from where numbers were taken. I would recommend concentrating on the long-term measurements of environmental factors, which is the strength of this manuscript.
L731- 767 The isotope data was already discussed in Wolff et al. There are some more points in the discussion of this manuscript, but they are not connected to any new results. The author has to consider if the isotope part should stay in the manuscript. Again, I think there is no substantial gain in presenting the same results again and they are not relevant for the time-series of the environmental data.
L776 Please rephrase the sentence. Why should primary production alone be a good predictor, this was never mentioned before? Maybe better state your positive result: Primary production in an area that is connected by water currents is important for the delivery of food to the sponge area. Please reflect these results also in your title.
Figure S1 and S2 Is this really necessary? Nothing was really done with this data.
Figure S3 Seems like the “HSB- ARGO” was above both areas. And the “LSB-ARGO” was mostly south of the study area.
Figure S4F The buoyancy frequency shows a very interesting peak in ~230 m above the high sponge area. This is a bit higher than the sponge ground itself but might be very important for the food delivery. This should be mentioned.
Figure S5 and S6 remove à is already published data.
Figure S7 y-axes are different, which makes it hard to compare. This figure is not referenced in the text. Refer to it or remove it.
Citation: https://doi.org/10.5194/egusphere-2024-245-RC1 -
RC2: 'Comment on egusphere-2024-245', Anonymous Referee #2, 16 Apr 2024
Dear Dr. de Froe and colleagues,
Please see the below my revision of your manuscript entitled "Year-long benthic measurements of environmental conditions indicate high sponge biomass is related to strong bottom currents over the Northern Labrador shelf." The manuscript presents an important dataset and would make an interesting contribution to science, at least from a regional perspective. The science and the writing are relatively good. I do have some comments that I would like to see addressed before considering this work publishable. I tagged it here as ''major revision", but it mostly concerns the Discussion and the Conclusion.
My main concerns are about the Discussion where a lot of speculation is made. In addition, I have the feeling that the authors make a wrong use of some references and/or use references and attribute this as a finding (e.g. "We showed that ... [citation]"). I would ask you to please carefully review your Discussion. Overall, I finished my reading thinking... so what? I provide more specific comments below.
There is also a lot of Figures/panels. I would advise that if data are not presented or necessary for the findings described, they could be removed.
INTRODUCTION: Good, nothing to add.
SECTION 2: METHOD
- L. 139: "This region is known for intense mixing and water mass transformation (Dunbar, 1951; Kollmeyer et al., 1967; Griffiths et al., 1981; Drinkwater and Jones, 1987; Yashayaev, 2007)"
-> The Yashayaev paper is not about mixing in Hudson Strait and should be removed.- L. 140: "four distinct flow components can be identified (Figure 1A...)"
-> There is no flow component in Figure 1...- Figure 1: There is a big void at 61N. Is it because there is no sponge or because it was not sampled? (e.g. it is a closure?). If the latter, it should be clearly stated that the sampling is not representative. Overall, it looks like there is sponge almost everywhere that was sample (very little number of red dots).
- Figure 1 (related to point above): It looks like the LSB site was just not sampled. How can you tell it has low biomass?
- L. 186: What is the vertical resolution of ADCP bins?
- L.286: "ADCP sensor at HSB were shifted for a small period of the deployment, implying the lander was occasionally moving a bit"
-> Like sea floor displacement? Or oscillation and coming back? I have trouble to picture what you mean and what could have caused such a displacement.- L. 304: "extracted from weekly ice charts (Canadian Government, 2022)."
-> Please verify is this is the correct way to cite this document.RESULTS:
- L. 316: "The temperature changes from cooling to warming with depth signify the Cold Intermediate Layer (CIL)."
-> This is a weird sentence. Can you expand?- L. 322: "The bottom oxygen concentrations at the lander stations were, for both transects, relatively depleted compared to the deep water CTD transects at similar depths."
-> 250 uM/L is still pretty high!- Figure 3 caption:
-> is it the "surface circulation"?
-> What are the dots and the lines in panel B?- Figure 12: Would it be possible to have error bars?
DISCUSSION:
This is that should be revised in depth.- L. 519: "Our findings confirm previous work which showed that Irminger Water is gradually cooled while moving southward by mixing with the Baffin Island Current (Cuny et al., 2002)"
-> How your study confirms this?-L. 521: "our Argo float profiles..."
-> Argo profiles are public. I would rephrase, these are not "yours".- L. 523: "For example, the 350-450 m depth layer in the HSB area regularly showed presence of Irminger Water (>4.5 ºC), while Irminger Water was only sporadically measured at LSB (Figure 5B). Irminger Water might therefore be cooled and freshened in the area around HSB due to convergence and consequently mixing with the Hudson Outflow and Baffin Island Current."
-> I don't understand the reasoning. How do your discard different advection patterns? Or the fact that the moorings are at different depths?L. 528: " This time lag corresponds to an along slope velocity of 0.3 m s-1, which is close to the mean bottom current speeds measured at HSB (0.25 m s -1) and on the Labrador Slope (0.11 – 0.23 m s-1 ; Lazier and Wright, 1993). This supports earlier findings on the Labrador Shelf that found a connection between the Hudson Strait outflow strength and the southern Labrador Shelf water salinity (Sutcliffe et al., 1983; Myers et al., 1990)"
-> Again, I don't see how the former support the latter.L. 536: "These observations are thought to be related to the sources of the bottom water and circulation. Thus, intermediate water flows from Baffin Bay via the Davis Strait southward along the continental slope (Curry et al., 2014). This water mass, referred to as Baffin Bay Water (BBW), contains higher nutrient concentrations (e.g., 41.6 ± 25.5 μM Si(OH)4, 18.5 ±2.6μM NO3-; Sherwood et al., 2021) due to in situ remineralization of deep water circulating in the Baffin Bay basin (Jones et al., 1984; Tremblay et al., 2002; Lehmann et al., 2019). BBW mixes with water masses on the Labrador Shelf and Slope and Hudson Strait outflow water while flowing southward along the Labrador Slope, resulting in lower nutrient concentrations at the LSB compared to the HSB (Figure S4). The absence of high nutrient concentrations at the shelf/deep CTD station at both sites supports this interpretation."
-> I am not sure if your study shows this...
L.557: "Namely, such an efflux from the sediments would be quickly advected away by the high bottom tidal currents, while nutrient concentrations were elevated up to 100 meters above the bottom (Figure 4 B & C)"
-> Can you rule out advection from upstream? sediment efflux at the site would be advected, but efflux from upstream can be advected at the site of the measurements... I don't think that your explanation is satisfactory."
L. 563: "This study provides the first concurrent long-term measurements of hydrodynamic and environmental conditions at a high-and low
sponge-biomass site."
-> You mean specific to these sites or worldwide?
L. 578: "Temperature increased gradually from summer until December, which is measured previously on the Labrador upper slope and attributed to Irminger Water (Cuny et al., 2002)."
-> The temperature increase is attributed to the IW? Can you clarify? A larger proportion of warmer IW throughout the year?
L. 589: "As the lander was placed ~500 m from the shelf break (Figure S2C&D), and bottom water could be transported ~5 km in the north-easterly direction in one semidiurnal tidal cycle (Figure 9A), this means that colder bottom water is transported on to the Labrador Shelf
from beyond the shelf break to the HSB lander site."
-> I am not sure I follow this reasoning... The temperature is colder above (on the shelf) compared to the slope. You say here that colder temperature is transported on the warm shelf...
L. 593: "Therefore, although higher variability in bottom water temperature has been attributed to the presence.
of internal waves at other sponge grounds (Roberts et al., 2018; Davison et al., 2019), we attribute the variability in our study area to tidal-
induced cross-slope transport of bottom water."
-> The main generation mechanisms for internal waves are the tides. So in this case do you mean the barotropic tide? If so, you would need to demonstrate that there is not internal waves generated (or propagating) at these sites.
L. 612-628: This paragraph is convincing (strong current = better feeding opportunities). All the rest that precedes seems highly speculative.
L. 637: "Our CTD profiles show elevated chl-a concentrations in the CIL (~150 m depth)"
-> It would be nice to have the chl-a profile in figure 3A.L. 638: The fact that primary production rates are comparable above the two lander station site s (Frajka-Williams and Rhines, 2010), suggests that differences in primary production alone are insufficient to explain the differences sponge biomass between regions."
-> This statement is problematic. Frajka-Williams paper is not about these 2 lander sites but rather compared the Northern vs Central Labrador Sea.L.645-669: This whole paragraph is highly speculative. The authors talk about seasonal sea ice and spring bloom dynamics as if there was no interannual changes (while they are actually quite large!). The whole paragraph needs to be better backed up by the literature review, or by new data.
CONCLUSION
-> So what? how this study contributes to science? Can you highlight the main findings? The results that are currently recalled in the Conclusion looks to me things that were already known...
MINOR COMMENTS:
- L. 184: mHz -> MHz- Figure 4: xlabel is cut.
- L. 505: "is known" -> "are known"Citation: https://doi.org/10.5194/egusphere-2024-245-RC2
Viewed
Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 223 | 0 | 0 | 223 | 0 | 0 |
- HTML: 223
- PDF: 0
- XML: 0
- Total: 223
- BibTeX: 0
- EndNote: 0
Viewed (geographical distribution)
Since the preprint corresponding to this journal article was posted outside of Copernicus Publications, the preprint-related metrics are limited to HTML views.
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1