Publication Date:
2022-08-15
Description:
Macroalgae (or seaweed) aquaculture can potentially
provide many ecosystem services, including climate
change mitigation, coastal protection, preservation
of biodiversity and improvement of water quality.
Nevertheless, there are still many constraints and
knowledge gaps that need to be overcome, as well
as potential negative impacts or scale-dependent
effects that need to be considered, before
macroalgae cultivation in Europe can be scaled up
successfully and sustainably. To investigate these
uncertainties, the Expert Working Group (EWG) on
Macroalgae was established. Its role was to determine
the state of knowledge regarding the potential of
macroalgae culture in providing climate-related
and other ecosystem services (ES) and to identify
specific knowledge gaps that must be addressed
before harvesting this potential. The methodological
framework combined a multiple expert consultation
with Delphi process and a Quick Scoping Review
(QSR). To analyse the outcome of both approaches,
the EWG classified the findings under the categories
Political, Environmental, Social, Technical, Economic
and Legal (PESTEL approach) and categorised the
ES based on the CICES 5.1 classification.
Although representative stakeholders from many
different disciplines were contacted, the majority
of responses to the Delphi process were from
representatives of academia or research. While
the results of each method differed in many ways,
both methods identified the following top six
ecosystem services provided by seaweed cultivation:
i) provisioning food, ii) provisioning hydrocolloids
and feed, iii) regulating water quality, iv) provisioning
habitats, v) provisioning of nurseries and vi) regulating
climate. Diverse technological knowledge gaps
were identified by both methods at all scales of the
macroalgae cultivation process, followed by economic
and environmental knowledge gaps depending on the
method used. Based on suggestions from the expert
respondents in the Delphi process, there is a clear
need for an European-wide strategy for reducing risks
for seaweed producers, providing clear standards
and guidelines for obtaining permits, and providing
financial support to improve technological innovation,
that will ensure consistent quality. Legal (e.g., safety
regulations), economic (e.g., lack of demand for
seaweeds in many countries) and technological (e.g.,
production at large scale) constraints represented
almost 70% of the total responses in the Delphi
process, whereas environmental and technical
constraints were more dominant in the literature. The
most commonly identified potential negative impacts
of macroalgae cultivation both among the expert
responses and the reviewed articles were unknown
environmental impacts, e.g. to deep sea, benthic and
pelagic ecosystems.
The present study provides an assessment of
the state of knowledge regarding ES provided by
seaweed cultivation and identifies the associated
knowledge gaps, constraints and potential negative
impacts. One of the main hurdles recognised by
the EWG was the understanding of ES themselves
by the different stakeholders, as well as the issue
of scale. Studies providing clear evidence of ES
provided by seaweed cultivation and/or valorisation
of these services were lacking in the literature, and
some aspects, like cultural impact etc. were missing
in the responses to the questionnaires during the
Delphi process. The issue of scale and scaling-up
was omnipresent both in assessing the ES provided
by seaweed cultivation and in identifying knowledge
gaps, constraints and potential negative impacts. For
example, the ES provided will depend on the scale of
cultivation, the main technological knowledge gaps
were often related to scale of cultivation. Likewise at
a large scale of operations, there could be multiple
associated potential side effects, which need to be
further investigated. Based on the outcomes of
this investigation, we provide an outlook with open
questions that need to be answered to support
the sustainable scaling-up of seaweed cultivation in
Europe.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Other
,
NonPeerReviewed
Format:
application/pdf
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