11.—(1) The 2030 species abundance target is that the overall relative species abundance index on the specified date indicates that the decline in the abundance of species has been halted.
(2) The specified date for the 2030 species abundance target described in paragraph (1) is 31st December 2030.
12.—(1) The 2030 species abundance target is to be measured by calculating the difference between the overall relative species abundance index for the years 2029 and 2030 in order to establish whether the overall relative species abundance index for the year 2030 is the same as, or higher than, the overall relative species abundance index for the year 2029.
(2) The overall relative species abundance index for a year is derived from the calculation of the geometric mean of the relative species abundance indices for every species listed in Schedule 2 for that year, which is smoothed to reduce the impact of between-year fluctuations in data collected over time.
(3) The same methodology must be used to determine the overall relative species abundance index for each year.
(4) In this regulation—
“baseline index” means the index value of 100 for any species in the first year that it is included in that relative species abundance index;
“geometric mean” means a mathematical process where a series of numbers are multiplied together and then the “n”th root of the product is calculated, where “n” is equal to the length of the series;
“relative species abundance index” for a species means an index which—
is an annual measure;
provides a standardised measure of abundance of that species across England; and
is expressed as a value relative to 100, where—
100 is the baseline index for each species in the first year that it is measured in that relative species abundance index; and
0 means no sightings of that species were recorded in a year(1).
(5) Where a species listed in Schedule 2 appears in more than one dataset that meets the criteria referred to in sub-paragraphs (a) and (b) of the definition of “relative species abundance index” in paragraph (4), the relative species abundance index for that species is calculated—
(a)in the case of a species listed in Schedule 2 that is a plant, from the average value of species abundance for that species derived from all the species abundance datasets in which it appears;
(b)in the case of a species listed in Schedule 2 that is an animal, from the species abundance dataset that the Secretary of State considers best provides—
(i)an annual measure; and
(ii)a standardised measure of abundance of that species with the widest coverage across England.
(6) For the purposes of paragraph (4), an index is only to be used if it is calculated using the same methodology each year.
13. For the purposes of section 6(1) of the 2021 Act, the reporting date for the target in regulation 11 is 15th April 2032.
14. The long-term biodiversity target to reverse the decline of species abundance is that the overall relative species abundance index by 31st December 2042 is—
(a)higher than the overall relative species abundance index for 31st December 2022; and
(b)at least 10% higher than the overall relative species abundance index for 31st December 2030 (the specified date for the 2030 species abundance target).
15.—(1) The long-term biodiversity target to reverse the decline of species abundance is to be measured by calculating the overall relative species abundance index for the following dates—
(a)31st December 2022;
(b)31st December 2030; and
(c)31st December 2042.
(2) Regulation 12(2) to (6) applies in relation to the measurement of the long-term biodiversity target to reverse the decline of species abundance as it applies to the measurement of the 2030 species abundance target described in regulation 11.
16. For the purposes of section 6(1) of the 2021 Act, the reporting date for the target in regulation 14 is 15th April 2044.
If the value of the relative species abundance index is 50, this means that the abundance of that species has decreased by 50% compared to the first year of measurement. If the value of the relative species abundance index is 200, this means that the abundance of that species has doubled compared to the first year of measurement.