Changes in the composition and abundance of ichthyoplankton along environmental gradients of the southern Baltic Sea
, , et | 10 déc. 2019
À propos de cet article
Article Category: Research Article
Publié en ligne: 10 déc. 2019
Pages: 328 - 336
Reçu: 15 févr. 2019
Accepté: 23 avr. 2019
DOI: https://doi.org/10.2478/ohs-2019-0030
© 2019 Faculty of Oceanography and Geography, University of Gdańsk, Poland
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Figure 1
Figure 2
Figure 3
Abundance of fish species (n m–3) recorded in the southern Baltic Sea in May and June 2015
| species | life stages of fish | sites | |||||||
|---|---|---|---|---|---|---|---|---|---|
| GA1 | GA2 | GB | IBY5 May | RS | GG | GGd | Krynica | ||
| eggs | 5.45 | 4.28 | 7.58 | 15.51 | 3.62 | 1.13 | 7.17 | 0.00 | |
| larvae | 1.26 | 2.24 | 0.52 | 0.68 | 1.45 | 0.39 | 1.50 | 0.00 | |
| larvae | 0.19 | 0.19 | 0.09 | 0.00 | 0.24 | 0.04 | 0.20 | 0.00 | |
| eggs | 0.00 | 0.00 | 2.57 | 1.18 | 1.95 | 0.00 | 0.00 | 0.00 | |
| eggs | 0.00 | 0.00 | 0.00 | 0.00 | 2.15 | 0.00 | 0.04 | 0.00 | |
| larvae | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.04 | 0.00 | |
| eggs | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.08 | 0.00 | |
| larvae | 0.00 | 0.00 | 0.00 | 0.00 | 0.05 | 0.00 | 0.00 | 0.00 | |
| larvae | 0.00 | 0.19 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 1.56 | |
| larvae | 0.09 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |
| larvae | 0.09 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |
| larvae | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.07 | 0.00 | 0.00 | |
The size of sprat eggs in stage I at different sites and depth layers
| site | haul | number of eggs | mean [mm] | min. [mm] | max [mm] |
|---|---|---|---|---|---|
| GA1 | 0–2 | 2 | 1.48 | 1.4 | 1.55 |
| 0–25 | 12 | 1.39 | 1.3 | 1.55 | |
| 0–46 | 14 | 1.4 | 1.2 | 1.55 | |
| GA2 | 0–2 | 10 | 1.45 | 1.3 | 1.55 |
| 0–25 | 11 | 1.45 | 1.25 | 1.6 | |
| 0–46 | 6 | 1.31 | 1.25 | 1.35 | |
| GB | 0–2 | no data | |||
| 0–27 | no data | ||||
| 0–94 | 20 | 1.36 | 1.25 | 1.45 | |
| RS | 0–65 | 17 | 1.36 | 1.3 | 1.5 |
| 0–91.5 | 20 | 1.45 | 1.3 | 1.55 | |
| GG | 0–60 | 8 | 1.44 | 1.4 | 1.5 |
| 0–103 | 15 | 1.39 | 1.3 | 1.5 | |
| GGd | 0–2 | no data | |||
| 0–53 | 14 | 1.38 | 1.2 | 1.45 | |
| 0–110 | 7 | 1.33 | 1.2 | 1.45 |
Characteristics of the sampling sites in the southern Baltic Sea in 2015
| Site | Coordinates | Date | Depth layer [m] | Bottom depth [m] |
|---|---|---|---|---|
| Arkona Deep 1 | 55°0ʹ0.36ʹʹN |
07.06.2015 | 2–0 |
46.10 |
| Arkona Deep 2 | 55°9ʹ15.48ʹʹN |
08.06.2015 | 2–0 |
46.90 |
| Bornholm Deep | 55°10ʹ13.08ʹʹN |
09.06.2015 | 2–0 |
96.10 |
| BB23 | 55°17ʹ31.2ʹʹN |
22.06.2015 | 2.5–87.5* | 94.00 |
| IBY5 | 55°14ʹ509ʹʹN |
29.05.2015 | 55–0 |
86.00 |
| Slupsk Furrow | 55°7ʹ49.08ʹʹN |
09.06.2015 | 2–0 |
93.00 |
| Gotland Deep | 55°28ʹ41.88ʹʹN |
10.06.2015 | 2–0 |
109.00 |
| Gdansk Deep | 54°30ʹ24.48ʹʹN |
10.06.2015 | 2–0 |
108.58 |
| Krynica | 54°14ʹ0.6ʹʹN |
10.06.2015 | 2–0 |
22.20 |
The number of sprat early developmental stages (n m–3) at four of the examined sites where the largest number of the early stages of development occurred
| site | development stage | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| I | II | III | IV | V | yolk-sac stage | pre-flexion | flexion | post-flexion | |
| GB | 4.29 | 2.15 | 0.81 | 0.33 | 0.00 | 0.52 | 0.00 | 0.00 | 0.00 |
| IBY5 May | 11.41 | 2.73 | 1.37 | 0.00 | 0.00 | 0.68 | 0.00 | 0.00 | 0.00 |
| RS | 2.60 | 0.44 | 0.48 | 0.05 | 0.05 | 0.98 | 0.10 | 0.24 | 0.13 |
| GGd | 4.40 | 0.53 | 1.91 | 0.29 | 0.04 | 1.34 | 0.16 | 0.00 | 0.00 |