DOI: 10.5281/zenodo.15074712
title: Experimental Data to" Small-scale thermal habitat variability may not determine seagrass resilience to  climate change"

description: Experimental Data to” Small-scale thermal habitat variability may not determine seagrass resilience to  climate change”

The study investigated the effect of microclimate differences across ten seagrass meadows in the Koster Sea archipelago, located on the Swedish west coast. Environmental data were combined with genetic and experimental analyses to evaluate how local microclimatic conditions influenced seagrass resilience and response to a changing climate. This integrated approach provided insights into the interaction between environmental variability, genetic diversity, and the adaptive capacity of seagrass meadows.

Field and Genetic Data related to this can be found at 10.5281/zenodo.15074855

 

 
description: Experimental Setup and Treatments:

Eelgrass (Zostera marina) was collected from ten meadows in the Koster Sea archipelago, Swedish west coast, between June 28 and July 2, 2021. Samples were taken by scuba diving at 1–3 m depth. Each meadow was approximately 7 km apart (range: 1.5–14 km). Eelgrass shoots were transported to Tjärnö Marine Laboratory, where they acclimated in flow-through seawater for ~20 days.

Experiments were conducted in BALTOTRON outdoor mesocosms at Tjärnö Marine Laboratory. Eelgrass shoots were planted in 12 L bags with sediment and distributed across ten 900 L tanks. Treatments included:



Ambient conditions – Natural temperature and salinity fluctuations recorded at the station.

Climate change conditions – +4.7°C warming and -5.5 PSU freshening, based on long-term data


Response Traits and Measurements

Before the Experiment:



Total Wet Weight Start (g): The combined wet weight of all plant components at the beginning of the experiment.

Leaf Number Start: The number of leaves per plant at the start.

Infection Labyrinthula (Start): Initial infection levels with Labyrinthula (presence/ absence).


After the Experiment:



Dead End: Individuals that did not survive until the end (1), alive (0)

Wet Weight Leaf End (g): Wet weight of leaves at the end.

Leaf Number End: Total number of leaves at the end.

Wet Weight Roots End (g): Wet weight of roots at the end.

Wet Weight Total End (g): Total wet weight (leaves + roots) at the end.

Shoots End: Number of shoots per plant.

New Leaf End: Number of new leaves grown during the experiment.

Dry Weight Shoots End (g): Dry weight of shoots.

Dry Weight Roots End (g): Dry weight of roots.

Dry Weight Total End (g): Total dry weight (leaves + roots).

Infection Labyrinthula (End): Infection levels with Labyrinthula at the end (presence/ absence).


 

The increase in, for example, wet weight and number of leaves was calculated as the difference between the start and end values for each measured trait.

Differences in growth and wet weight were calculated to evaluate the effect of the climate change treatment, using a paired-design where one shoot from the same genetic individual was assigned to the "ambient" treatment and the other to the "climate change" treatment.

 




Location (short)
Location (long Name)
Lat. (°N)
Long. (°E)


Fla
Flatskär 
58.856835
11.140161


Gas
Gåsholmen 
58.878628
11.134688


Koc
Kockholmen 
58.83428
11.140891


Kos
Koster 
58.882538
10.991989


Nyc
Nycklebykilen 
58.888803
11.166456


Ram
Ramnekroken 
58.898535
11.143091


Sty
Styrsö 
58.905591
11.105685


Tan
Tångeholmen 
58.896587
11.186828


Tja
Tjärnöbo 
58.873716
11.191207


Vat
Inre Vattenholmen 
58.877199
11.115649