Description: Seed-based restoration is a promising approach to accelerate the slow natural recolonization of Zostera marina meadows. In this study, seed-based restoration was investigated through the injection of seeds into the sediment using syringes. Parallel laboratory and field experiments were conducted to examine the germination success over time under both simulated and natural field conditions. A laboratory experiment was conducted in the climate chambers of GEOMAR Helmholtz Centre for Ocean Research Kiel. Twelve replicate aquaria, each containing 6 boxes of 18 cm*13 cm*18 cm, were set up in a climate chamber. Each plastic box in the aquaria was filled with 6 cm of sandy sediment collected from sandbanks next to seagrass meadows in Falckenstein near Kiel (54°23'39.4N 10°11'23.6E). For sterilization, the sediment was autoclaved at 121°C for 20 minutes before use. Water was changed weekly, with approximately 30% replaced by filtered (50 μm and 5 μm filter cascade) Baltic Sea water with an ambient Baltic salinity of ranging from 14-16 PSU. The chamber simulated field conditions typical for the season, with 12 hours of light per day and a temperature of 10°C. In each box, a seed amount equivalent to the weight of 100 Zostera marina seeds was sown, based on the average seed weight determined prior to the experiment. Seeds were collected at two sites in Laboe and Falckenstein (Kiel Fjord) in July 2023 by snorkelers and scientific divers (Laboe: 54° 24' 48.53 N, 10° 13' 29.91 E; Falckenstein: 54° 23' 31.36 N, 10° 11' 31.15 E). They were overwintered in climate cabinets in darkness at 4°C and a salinity of 32 PSU, where they rotated every 6 hours for 1 minute. Different treatment combinations were tested, involving the factors Sowing Method (syringe (100 ml) with agar medium or Hand-Sown), Sowing Depth (2 cm or 4 cm), Origin of Seeds (Falckenstein or Laboe), and Fertilization of the Sediment (from the beginning, after germination, or none at all). The Hand-Sown method served as a control. To this end, the box was filled with about 4cm autoclaved sandy sediment. Then the seeds were evenly distributed on the surface and covered with either 2 cm or 4 cm of sediment before being gently lowered into the aquarium. For the syringe treatment, seeds were injected into the sediment embedded in an agar medium prepared by cooking Baltic Sea water with 1.8% agar (Agar-Agar, BioScience Grade, pulv., Carl Roth). Each syringe contained 90 ml of crumbly agar, 10 g of autoclaved sediment, 100 seeds and depending on the treatment either 1g charcoal powder or nutrients (P and N) were added. For the nutrients, according to the Redfield ratio N:P = 16:1, 100 μL of nitrogen and 10 μL of phosphorus were used per 90 mL of agar. There were three timing treatments for "Timing of Nutrients in the Sediment". "Nutrients from Beginning", "Nutrients after Germination" and "no Nutrients". The treatment was the same for all boxes within one aquarium to avoid potential influence on the surrounding water. As fertilizer "osmocote Langzeitdünger 6 Monate" (N P 19+9) was used. In the boxes with "Nutrients from Beginning", two pellets were inserted with tweezers into the sediment directly after sowing. In the boxes with "Nutrients after Germination", the same treatment started on April 29, 2024, after many of the seedlings had already developed some green leaves. The seeds were sown on March 4, 2024, and from March 21 to May 25, 2024, emerging seedlings were counted three times per week. Seedlings with only cotyledons and seedlings with developed green leaves were counted together in the beginning and separately from April 24, 2024, onwards.
Global identifier:
Doi(
"10.1594/PANGAEA.993870",
)
DataMeasurements(
DataMeasurements {
domain: Unspecified,
station: None,
measured_variables: [
"Aquarium number",
"DATE/TIME",
"Date/time end, experiment",
"Date/time start, experiment",
"Day of experiment",
"Event label",
"Experimental treatment",
"LATITUDE",
"LONGITUDE",
"Light intensity",
"Salinity",
"Salinity, maximum",
"Sampling",
"Seedlings",
"Species, unique identification",
"Temperature, water",
"Type of study",
"Zostera marina",
],
methods: [],
},
)
Tags: Kunststoff ? Düngemittel ? Meerwasser ? Nährstoff ? Phosphor ? Stickstoff ? Wiese ? Geografische Koordinaten ? Laubblatt ? Saatgut ? Temperatur ? Wiederansiedlung ? Salzgehalt ? Seegraswiese ? Studie ? Sediment ? Meeresgewässer ? Klimaforschung ? Freilandversuch ? Wasseraufbereitung ? Ostsee ?
Region: Falckenstein, Germany
Bounding boxes: 10.1919849° .. 10.2249744° x 54.3920434° .. 54.4134802°
License: Creative Commons Namensnennung 4.0 (Data access requires registration)
Language: Englisch/English
Modified: 2026-05-18
Last harvest: 20.05.2026 01:49
Time ranges: 2023-07-10 - 2024-05-24
Accessed 4 times.