Supplementary written Evidence submitted by Buglife (INS0046)

The Invertebrate Conservation Trust

 

Following on from giving oral evidence on 12th July 2023 the additional evidence below may be of further assistance to the Committee.

 

1)      Insect Population Trends

 

The NFU written submission is exceptional in claiming that insect biodiversity declines “have slowed, stopped, or even shown some recovery in recent decades”.  The submission relies on a single paper to support of this controversial claim - Carvalheiro et al. (2013)[1].  The first point to note is that this paper is based on occupancy of 10km squares not on insect abundance and, as has been explained to the committee, such data tends to underestimate change in abundance as 1 bee in a 10km square scores the same as 10,000 bees. A reanalysis of the data in the referenced paper showed that the rapid geographic spread of two species of bee in the Netherlands had a disproportional effect on the statistical analysis, and if these two bees (which do not occur in the UK) are removed from the analysis then the conclusion that declines are decelerating is no longer supported by the data (van Dooren 2016[2]) and indeed when reanalysed the data instead shows declines in species richness for both bumblebees and other bees (van Dooren 2019[3]).

 

The underlying UK data set used in the above study is the same distribution dataset used by the JNCC to monitor changes in populations of hoverflies and bees for the UK biodiversity indicators.  The most recent analysis of this data – 1980 – 2019[4] - is subsequent to the data quoted by the NFU as showing a short-term average occupancy decline between 2012 and 2017 of 2% - “little change”, the new short-term assessment shows a decline in presence of 5.6% between 2014 and 2019 - “deterioration”.  This trend in distribution for these two groups of flying insects is entirely compatible with the much steeper reduction in wider insect abundance observed in the Bugs Matter data and other abundance-based studies. Therefore, there is no solace in the UK distributional dataset for those hoping that UK pollinator populations may be showing signs of recovery.

 

Meanwhile, bearing in mind the evidence presented to the committee of the negative impact of domesticated Honeybees on wild pollinator populations, it is concerning that simultaneously the numbers of Honeybee hives in the UK has increased by 36,000 in just 5 years[5].

 

2)      Freshwater Invertebrate Populations

 

Evidence has been presented to the Committee that in recent years there has been an improvement in invertebrate populations in freshwater habitats (e.g. van Klink et al. 2020[6] and Pharaoh et al. 2023), as a result of water quality improvements associated with the Water Framework Directive 2000. This improvement is against a backdrop of severe declines in the population levels of sensitive aquatic groups of invertebrates such as mayflies and stoneflies as detected in the Millenium Chalk Streams Survey[7] populations, as there was little abundance data collected by the statutory agencies prior to 1990 it is not possible to ascertain if invertebrate populations have recovered to the probably significantly higher levels present before 1980. 

 

An even more important caveat from an invertebrate abundance perspective is that the data presented in recent papers relates almost entirely to the lower reaches of rivers, with some data also available for large lakes.  This is a significant caveat as the vast majority of water bodies are small waterbodies such as ponds and ditches, and these habitats are disproportionately important for invertebrate biodiversity[8].  There are at least 4000 species of freshwater invertebrate in the UK, about two thirds of which can live in ponds, and the British Red Data Books list about 300 threatened freshwater invertebrate species, over two thirds of which are found in ponds[9]. As of the most recent survey in 2007 only 8% of ponds are in good condition[10], while 70% of headwater streams in southeast England are degraded[11].

 

When the Water Framework Directive was conceived it was not the intention that it should only relate to large water bodies, it was supposed to secure the good status of all waterbodies.  Defra should review the current application of the WFD and of freshwater monitoring programmes to ensure there is adequate inclusion and coverage of small water bodies.

 

 

3)      Flowers for Pollinators in Gardens

 

The evidence is very clear that native plants in gardens provide substantially better support to native pollinators than ‘near-native’ or ‘exotic’ plants.

 

The Royal Horticultural Society Plants for Bugs project, which Buglife initially advised in terms of scientific methodology, included three separate analyses 1) of flower visiting insects, 2) of invertebrates living in the vegetation and 3) of invertebrates living at ground level.

 

The flower visiting study (Salisbury et al. 2015[12]) found that for the most species rich groups - solitary bees and hoverflies - native plants were visited most frequently, although solitary bees were also strongly attracted to one species of the ‘near-native’ flower used in the study. While exotic flowers were generally shunned by all groups of pollinators, ‘near-native’ flowers were commonly visited by domestic Honeybees, when Honeybees were removed from the analysis there tended to be more pollinators recorded on native flowers than ‘near native’ flowers.

 

In the vegetation study (Salisbury et al 2017[13]) total invertebrate abundance was highest among native-plants, fewer invertebrates were found among plants on ‘near native’ plots and abundance was lowest in the exotic plots.

 

In the soil surface study (Salisbury et al 2020[14]) total invertebrate abundance was highest among native-plants, particularly for herbivores and parasitoids. Herbivores and parasitoids are often also pollinators so finding that native plants support the highest populations of these groups is significant for maintaining pollination services – nocturnal as well as diurnal. Only omnivores were most abundant in the ‘near native’ plots and no groups were most abundant in the exotic plots.

 

While the evidence does indicate that garden plants regardless of origin have some value for supporting native pollinators, and gardens serve a range of purposes, not just sustaining biodiversity, the evidence is clear from these and other studies that native plants in gardens will give the greatest return in terms of maintaining native invertebrate and pollinator abundance.

 

4)      Scientific Investment

 

The Committee has been presented with a wide range of scientific evidence relating to many aspects of the status of pollinators and pollination services.  There are complex issues that are interacting across landscapes in intricate ways.  While volunteers can, through citizen science, help to provide us with insights and data that helps to illuminate the problems and solutions, fundamentally progress is dependent on a strong science base.

 

As we are currently in a biodiversity crisis one might think that a commensurate increase in funds would have been channelled through the science councils into understanding the nature of the crisis.  However, the recent “The Trends in UK Funding for Ecology” report produced by the British Ecological Society analysed changes in the amount of United Kingdom Research and Innovation (UKRI) funding available for ecological research in the UK. It found that although funding for ecological research increased 1.5 times between 2006 and 2021, funding for other research areas increased 2.8 times. This means that the proportion of UKRI funding given to ecology decreased significantly over this period[15].

 

In addition, invertebrate biodiversity is only a small part of current ecological research budgets and there seems to be little improvement.  It appears as if funds for scientific research are awarded to those who have received awards before, to do work that is expected to get lots of readers in high profile journals.  The effect produces a heavy bias towards the status quo that disadvantages those working in innovative ecological areas, such as investigating threats to pollinator populations. A number of scientific papers have been published highlighting the bias against invertebrate research funding[16] [17] [18] a phenomenon referred to as ‘institutional vertebratism[19].

 

Given the urgency of decline rates and the essential role of pollinators, invertebrates and biodiversity in sustaining life on earth there is a strong argument for Government to significantly increase the availability of funding for invertebrate ecology generally, and for long-term monitoring and studies specifically.

 

 

5)      National Pollinator Strategy Review

 

We note that the opportunity has not been taken though this Inquiry to undertake a detailed review of the progress made by the National Pollinator Strategy[20].  While there have been some limited successes as a result of the strategy, most notably the establishment of a UK wide Pollinator Monitoring Scheme, the strategy fails to address pesticide harm, habitat fragmentation or light pollution. 

 

The National Pollinator Strategy runs until 2024 and pollinator declines are rapid and should be urgently addressed.  Defra should be starting the process, including public consultations, of developing a fully resourced follow up plan so that the gaps in the previous plan are addressed, if they are not quickly tackled we stand little chance of meeting the international biodiversity commitment to restore pollinator services by 2030 or the Environment Act target to halt the decline in species populations by 2030, and then increase populations by at least 10% to exceed current levels by 2042.

 

We hope the committee will recognise the need to urgently review the National Pollinator Strategy and will make appropriate recommendations around process if not detailed content.

 

 

24 July 23


[1] https://onlinelibrary.wiley.com/doi/full/10.1111/ele.12121

[2] https://natureconservation.pensoft.net/article/9616/

[3] https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.5717

[4] https://oifdata.defra.gov.uk/themes/wildlife/D7/

[5] https://questions-statements.parliament.uk/written-questions/detail/2023-06-28/191515

[6] https://www.science.org/doi/10.1126/science.aax9931

[7] http://www.environmentdata.org/archive/ealit:1274/OBJ/19001627.pdf

[8] https://freshwaterhabitats.org.uk/wp-content/uploads/2020/01/New-Ponds-British-Wildlife-vol-22-p77-85.pdf

[9] The value of ponds for wildlife (Freshwater Habitats Trust) https://freshwaterhabitats.org.uk/wp-content/uploads/2015/10/The-value-of-ponds-for-wildlife-NEW.pdf

[10] https://nora.nerc.ac.uk/id/eprint/9622/1/N009622CR.pdf

[11] https://countrysidesurvey.org.uk/sites/default/files/CS_UK_2007_TR8%20-%20Streams%20Report.pdf

[12] https://besjournals.onlinelibrary.wiley.com/doi/pdfdirect/10.1111/1365-2664.12499

[13] https://link.springer.com/article/10.1007/s10531-017-1377-x

[14] https://link.springer.com/article/10.1007/s10531-019-01874-w

[15] https://www.britishecologicalsociety.org//wp-content/uploads/2023/03/BES_Funding_For_Ecology_Report.pdf

[16] https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0189577

[17] https://cdn.harper-adams.ac.uk/document/profile/Leather_Biologist_2009.pdf

[18] https://www.sciencedirect.com/science/article/pii/S0006320723000885

[19] http://cdn.harper-adams.ac.uk/document/profile/Leather_2013_Animal_Conservation.pdf

[20] https://www.gov.uk/government/publications/national-pollinator-strategy-for-bees-and-other-pollinators-in-england