The aim was to determine the possible impact of M. leidyi on the marine ecosystem and the risk for valuable resources in the 2 Seas area which may suffer due to large numbers of gelatinous zooplankton. Results were shared with stakeholders (environmental agencies, research and the public).
There were 3 objectives:
1) Assess the spatio-temporal distribution of M. leidyi
2) Insight in the physiology, feeding behaviour and predators of the species
3) Evaluating the potential environmental and socio-economic impact in the 2 Seas area.
MEMO provided a framework for monitoring, identification and preservation of M. leidyi (Activity 1). SOPs were developed and applied on existing and in a joint cross-border survey. Knowledge transfer was assured through several workshops. To predict the areas where M. leidyi is most likely to thrive, distribution maps and a habitat model were developed.
To determine the behaviour and trophic position of M. leidyi in the food web lab experiments were carried out (Activity 2) to give an insight in the reproduction, feeding and prey-predator interactions. These had to result in a life cycle model and an assessment of the possible impact of the species in the 2 Seas area.
Activity 3 aimed to develop an ecosystem model and an ecosystem approach, linked to a socio-economic study, to assess the potential ecological and economic costs of comb jelly outbreaks in the marine and coastal waters in the 2 seas region and to identify potentially vulnerable areas.

The procedures and results of MEMO were communicated in scientific publications and international conferences. Different stakeholders including academics, politicians and the public were informed on the possible threat of M. leidyi to the 2 seas marine ecosystem, through publications, workshops, steering committee meetings and an end user meeting (Communication & Dissemination).

In Activity 1 the aim was to characterize the spatio-temporal distribution of the comb jelly M. leidyi, based on Standardized Operational Protocols for sampling and preservation of gelatinous plankton (a1) and for species identification (a2), these were applied to existing and dedicated sampling surveys in the 2 Seas region (a3) and had lead to the development of distribution maps and a habitat model (a4).



(a1) SOPs for sampling and preservation of gelatinous zooplankton were developed

(a2) A method for the molecular-genetic identification of M. leidyi and other gelatinous plankton was used

(a3) Local and Interregional monitoring surveys and crossb-order survey to collect data and create an integrated database were done

(a4) Distribution maps and a habitat model were made



The aim of Activity 2 was a better understanding of the biology, physiology and feeding behaviour of M. leidyi, through lab experiments and field studies on reproduction (a1), feeding activities (a2) and stable isotope analyses (a3). This had to lead to different mathematical models, including prey – predator interactions (a4) and the development of a life cycle model (a5). These assessments were necessary to evaluate a potential outbreak of M. leidyi in the 2 seas region.



(a1) Determination of the fecundity and growth rate of M. leidyi

(a2) Assessment of the diet composition, prey selectivity, feeding rates and behaviour and the impact of M. leidyi in situ

(a3) Determination of trophic position of M. leidyi in the ecosystem

(a4) Determination of food competitors and prey - predators of M. leidyi

(a5) Development of an Individual Based Model of M. leidyi which will represent all key processes of the life cycle of this species (Particle tracking model with reproduction mechanism)



All partners are leading institutes in the bio-environmental monitoring of marine habitats in their respective countries, including the monitoring of gelatinous zooplankton. They all already collaborated in different EU projects and are involved in the ICES expert group on zooplankton ecology and deliver data to OSPAR.

Through the SOPs and surveys, the presence of M. leidyi was confirmed in the coastal areas, estuaries and harbours of France, the Netherlands and Belgium. Highest numbers were seen in late summer and fall in semi-enclosed basins. The species can reproduce and overwinter (low densities) here. The database allowed creating a habitat model for monitoring of areas where the species has not yet been seen enabling rapid response in case of a sudden bloom.
We succeeded to close the life cycle of the species. It's an opportunistic consumer of zooplankton, fish eggs and larvae and competes with zooplanktivorous fish. Energy is immediately converted into either growth or reproduction, which can be an explanation for its success. M. leidyi has a high tolerance for environmental variables, enabling rapid spread. The species was found in the stomach of herring and sprat.
An IBM model (physical and biological behaviour) was coupled with a hydrodynamic (GETM) model and an ecosystem model (ERSEM). The importance of temperature and estuaries for the presence of M. leidyi was shown.
A map with areas of high concentration/retention and survival of the species was created. There was a thorough collaboration with fishermen, tourists through the socio-economic questionnaire and meetings. Socio-economic analyses indicate that the impact of M. leidyi would be small. As yet, mitigation is not needed, but caution is required. A rise in water temperature, the exchange of ballast water and an increased pressure on our marine ecosystem can lead to substantial blooms and expansions into new territories, with potentially implications for fisheries, tourism and other commercial activities.
The results of the project were disseminated through meetings, the website, the newsletter, in scientific and more vulgarizing journals and magazines.

The scientific community was a direct beneficiary of the project because of sharing skills, knowledge, human resources and laboratory equipment. The SOPs that were developed for sampling, preservation and identification are uniform tools, which the scientific community can use.

The local and regional target groups at mid-term scale are the governmental and professional (fisheries, aquaculture, power plants, tourism) actors or stakeholders. Information on presence is useful as awareness rising in their daily activities; government can use knowledge on M. leidyi in the prevention of a possible invasion of M. leidyi. The information on presence and SOPs has an added value in various new or existing monitoring programs.
Information on survival conditions and potential predators of M. leidyi is essential information for fisheries and the preservation of marine productivity and biodiversity.
On longer time scale, the broader public benefits from MEMO. Knowing the distribution, dispersal and development of gelatinous zooplankton is very important for recreational activities and rising awareness, which is a first step in management. The socio-economic study assessed the perception of tourism and fishermen about jellyfish and showed that information is needed.
Furthermore, scientists, government and other stakeholders can use the knowledge, SOPs and models in support of communication with the public. MEMO can be used as pedagogical tool to introduce marine biology and, especially, the subject of invasive species to scholars and academics.

Within activity 1, SOPs were developed for sampling, preservation and identification. This allows that people in each territory use a uniform procedure and that further cross-border cooperation is made possible to tackle the problem of the invasive species M. leidyi. Furthermore a database with field data was composed and a prediction model was constructed for the presence of the species under different circumstances and in different areas. In this way, it is possible to monitor areas where M. leidyi has not been observed yet (eg. Great Britain) and react quickly in case of a possible outbreak.

In the 2nd activity, the trophic position of M. leidyi was determined. The fact that the species is a voracious predator on different types of zooplankton, fish eggs and larvae and has a high tolerance for environmental variables showed us what plays a role in his survival success and made the rapid expansion possible. This knowledge was needed to assess its possible impact in each territory.
In the 3rd activity models were set up showing the importance of temperature for the presence and density of M. leidyi. A further climate change can stimulate the success of M. leidyi in our regions. Models also showed the important role of estuaries, in which populations can produce large numbers of M. leidyi and can act as year-round source for the wider North Sea. Chances of M. leidyi invading UK waters by natural processes, however, are small. Socio-economic analyses showed that direct impacts of blooms would be rather small. However, when there would be nuisance by odor it would result in an impact on tourism. For the moment little is known by tourism on the species, but more information is needed on jellyfish and their possible causes and effects.
The stakeholders will be able to use the results of MEMO in their daily practice and the knowledge can be used to monitor, predict the possible impact and set up mitigation measures, if needed, to prevent an invasion of M. leidyi.

One of the aims of cross-border cooperation in EU is the joint management of natural risks. This is definitely the case for the threat posed by the invasive species M. leidyi in the 2 Seas area. An EU cooperation for monitoring, research and management measures was essential and was realised within the MEMO project.
Knowledge gaps related to M. leidyi were diverse and required expertise in various scientific fields.
MEMO was an opportunity to develop, improve and standardize methods and monitoring of the partners across the 2 Seas area. The cooperation stimulated sharing of expertise, databases, data analysis methods, model development. This was only possible in cross-border cooperation. With MEMO it was possible to cover a wide range of expertise and to perform research in the whole 2 Seas area. The outreach of the project contributes to a sustainable development within the 2 Seas area and facilitates and promotes a joint implementation of possible future management measures.

With MEMO, it was possible to cover a wide range of expertise and to perform research in the whole 2 Seas area. The outreach of the project contributes to a sustainable development within the 2 Seas area and facilitates and promotes a joint implementation of possible future management measures.
Also the Interreg 2 Seas project RINSE deals with risk assessment and management of invasive species.

Cross-border cooperation is needed to enlarge your study area, to deal with common themes and to share complementary expertise. To reach the aim and goals of a cross-border project, a good cooperation within the partnership to cover financial, administrative or scientific issues is needed. Regular communication among partners and between JTS and partnership was essential for the project success, as communication is not always that easy in the scientific world.

Results will remain available to the scientific world through peer-reviewed papers. The Standardized Operational Protocols on morphological and genetic identification of M. leidyi and other gelatinous plankton, will be published and can be implemented for monitoring purposes imposed by EU legislation, like the Marine Strategy Framework Directive, in case invasive gelatinous plankton species.
After the MEMO project, the website and the archived digital Newsletter will be maintained as separate module on the Lead partner website, and the main results will be published on the websites of the different partners. Extra funding will be sought by different partners to continue activities if certain aims were not achieved.
Different stakeholders and regulating bodies are informed of the distribution and the potential impact of M. leidyi and other gelatinous plankton in the 2 Seas region and can use information for monitoring or management purposed.

Cooperation and sharing of knowledge between partners was established. Thanks to MEMO, the research institutes got in contact with each other, another Interreg funded project MICRO did start in July 2012. Other fields of expertise and other researchers are working on it, but the research institutes are the same. Researchers got to know each other, will work together and keep on networking. Also networking with external institutes, agencies or stakeholders favour cooperation on the issue of invasive species. With MEMO the partnership is involved in the Interreg cluster SE FINS dealing on invasive species.

The Interreg 2 Seas Programme has funded 2 projects which focus on reducing the impact of invasive non-native species (INS) and predicting the impact of novel INS that are likely to arrive in near future. RINSE which focuses on freshwater INS and MEMO, focussing on marine species. An Interreg cluster between these 2 partnerships is running to create a valuable network of expertise across the 2Seas Area which will cover all of the habitats found in the coastal zone. The cluster will disseminate the results of both projects, identify gaps in the current knowledge on INS, highlight key actions to fill these gaps and review communication of both projects. Ideas for further collaborative work outside the cluster will be produced.
Furthermore knowledge gained on the distribution, SOPs and modelling of invasive species M. leidyi will be used by all partners in future research and published in joint papers.