Evidence gaps: what is not yet known, and how it will be found out

11.1 Why the gaps matter

Each gap stands between a general statement and a specific prediction. Modelled background fine particles at Kribi already exceed the WHO guideline (Chapter 4). But the margin left for the project depends on what a year of on-site monitoring shows. The small streams on the plateau may hold restricted-range fishes (Chapter 7), and only a survey in high and low water can tell. The land may have been fully released by its former users, or it may still be farmed (Chapter 8), and only a census and a legacy review can establish which. Until these questions are answered, any confident prediction would be guesswork.

The gaps fall into four groups:

• physical baselines that must be measured on site across seasons;
• biological and social surveys that must be done in the field, with communities;
• documents and data held by public authorities and other projects;
• technical and market questions that the engineering design must answer.

11.2 The gaps and how they will be closed

Table 11.1 Main evidence gaps and how they will be resolved

Source: Cameroon Steel analysis of the desk baseline; methods follow IFC guidance [G01][G02][G03][G04] and Décret 2013/0171/PM [L02].

11.3 The calendar is set by the seasons

Several surveys must catch particular conditions: low and high river flow, the dry-season window for earthworks and archaeology, the main wet season for drainage, and the turtle nesting season on the beaches. Figure 11.1 lays out an indicative calendar by month against Kribi’s rainfall seasons. Its message is simple. A credible baseline needs a full year and both seasons. Starting it as early as possible is the single most effective way to shorten the overall programme without cutting corners.

Source: Cameroon Steel analysis; seasons from Olivry, 1979 [E01]; turtle nesting season to be confirmed with the marine park authority.

11.4 Questions we cannot answer alone

Some gaps can only be closed by others, or jointly with them.

The zone’s strategic assessment. The 2016 order requires a strategic environmental assessment for industrial zones and industrial-port complexes [L03]. If one exists for Kribi, our assessment should build on it. If none exists, we will support its preparation (Chapter 9).

The land records. The files of the 2009 declaration of public utility and the 2010 compensation decree are held by the land administration and the port authority. We will ask for access as a first step of the land legacy review.

Existing baselines. The port, the gas power plant, the motorway and the rail and mining projects have each produced environmental studies and, in some cases, years of monitoring. Shared access would improve every project’s assessment, including ours, and would reduce the burden on communities who are asked the same questions repeatedly.

Status of species. The global statuses in Chapter 7 were checked on the IUCN Red List (version 2026-1) for this edition [B10]; they will be checked again when the assessment is filed, because statuses change. Key Biodiversity Area and Important Bird Area designations for the area of influence need confirming through IBAT, which requires a subscription. We will include it in the assessment budget.

11.5 What we will do with what we learn

The purpose of the baseline is to change the project where the evidence requires it. If the surveys find a stream with a restricted-range fish, the layout will move away from it. If the census finds current users of the land, we will try to avoid displacing them through the layout before we plan compensation. If the air monitoring shows less headroom than expected, the controls will be strengthened before the permit is sought. If the Indigenous Peoples screening triggers FPIC, the affecting activities will wait for the outcome. We will publish the baseline data quarterly as they are collected (Chapter 10), so that others can check our reasoning as well as our conclusions.