The North Pacific Diatom Species Neodenticula seminae in the Modern and Holocene Sediments of the North Atlantic and Arctic

Round 1

Reviewer 1 Report

This is an interesting research problem and I would be happy to give my support for its publication. However, in the present form it needs attention in two aspects and I see it is much work to be done. First aspect is English. English of the manuscript needs extensive editing. Throughout the manuscript authors tend to use rather jargon than the language of science. It shall be clearly said that they tackle with observations not findings, for instance. The second aspect of the paper a review of N. seminae spatial and stratigraphic distribution is interesting and welcome, but again it suffers from the English level. The weak point of the manuscript is link between the hydrological shifts in North Atlantic and appearance of N. seminae. The core from the Fram Strait analyses by the present senior author may suggest that the species predates the hydrological shift. 

I am not happy with the delimitation of the species distribution in the North Atlantic. Personally I have observed it in a core taken from the longitude of 30 degree E. The results of my observations have not been published yet. The papers current authors refer to in favor of the limitation of the Eastward extent have been focused on different issues and possibly the temporal resolution was too low. To observe the N. seminae further south in the North Atlantic high resolution sampling is necessary. I counted samples taken at 0.5cm interval. 

I suggest that authors re-think the manuscript and its content and definitely ask a native English speaker to revise the manuscript. With this hope I recommend a major revision.

Comments for author File: Comments.pdf

Author Response

Please, see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The North Pacific endemic diatom species Neodenticula seminae in the modern and Holocene sediments of the North Atlantic and Arctic

Alexander Matul, Galina Kh. Kazarina

The manuscript presents a new data on distribution Neodenticula seminae in the recent and Holocene sediments of the North Atlantic and Arctic. In 1999, large numbers of the Pacific diatom Neodenticula seminae were found in plankton samples in the Labrador Sea as the first record in the North Atlantic for more than 800 000 years (Reid et al., 2007). Since then interest in this species has grown, because its distribution makes it possible to trace the circulation between the waters of the Pacific and Atlantic oceans at present and in the Past. For the first time, data on the distribution of this species in the seas of the Eastern Siberian Arctic have been generalized. The manuscript is justified and well illustrated.

 

Comments and recomendations to the Authors

 

Line 2. I would not call Neodenticula seminae endemic because it was quite widespread in mid to high latitudes of the North Pacific and North Atlantic in the Pleistocene and at present.

Line 35, 42, 46 et al. Latin names of species should be given in italics

Line 71. Figure 1. Red arrows look like yellow, blue arrows look like light purple

Line 33. replace (Fernandez et al., 2014) with reference number [69] or [4]. In last case, check and change the entire order of reference numbers.

Lines 104-107. The reference to Onodera et al., 2015 is not quite correct. This work is dedicated to the Arctic Ocean, which is evident even from the title of the article: Diatom flux reflects water-mass conditions on the southern Northwind Abyssal Plain, Arctic Ocean.

Canadian and Russian researchers have also studied diatoms, including Neodenticula seminae, in sediment traps, for example, Tsoy I. B., Wong C. S. (1996). Diatom fluxes in the deep North West Pacific and preservation; Tsoy et al. (1998). Seasonal Fluxes of microplankton in the Meiji Guyot Area (Northwestern Pacific). It is probably more important to focus on N. seminae research in sedimentation traps, rather than on the country that conducted these studies.

Line 119. Figure 3. Blue bar looks like purple

Line 241. Delete (

Lines 244-248. A desirable reference here is to [5] (Reid et al., 2007), since a similar conclusion has already been made there.

Line 256-258. Add to [68-70] a reference [5] (Reid et al., 2007), since this suggestion was also discussed there: ‘An alternative explanation for the introduction of the species via ballast water exchange in the open ocean seems unlikely as shipping volumes were low in the Northwest Atlantic in 1998/1999’. Another article that discussed the introduction o the Neodenticula seminae species via ballast waters was omitted. This is ‘Morphological and phylogenetic comparisons of Neodenticula seminae (Bacillariophyta) populations between the subarctic Pacific and the Gulf of St.Lawrence’ (2010) by Michel Poulin, Nina Lundholm, Lyse Bérard-Therriault et al.

 

Some misprints are highlighted in the text.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I am fine with the English edits, though marked a few points on the text. The revised version addressed all my concerns.